Integration of Blockchain in Accounting and ESG Reporting: A Systematic Review from an Oracle-Based Perspective

Abstract

The Bitcoin network is a sophisticated accounting system that facilitates consensus and verification of transactions through cryptographic proof, eliminating the need for a central authority. Given its success, the underlying technology, generally referred to as blockchain, has been proposed as a means to improve legacy accounting and reporting systems. However, integrating real-world data into a blockchain requires the use of oracles: third-party systems that, if poorly selected, may be less decentralized and transparent, potentially undermining the expected benefits. Through a systematic review of the existing literature, this study investigates whether research articles on the integration of blockchain technology in accounting and reporting have addressed the limitations posed by oracles, under the rationale that the omission of oracles constitutes a theoretical bias. Furthermore, this study examines oracle-based solutions proposed for reporting applications and classifies them based on their intended purpose. While the overall consideration of oracles remains limited, the findings indicate a steadily increasing interest in their role and implications within accounting, auditing, and ESG-related blockchain implementations. This growing attention is particularly evident in ESG reporting, where permissioned blockchains and attestation mechanisms are increasingly being examined as practical responses to data verification challenges.

1. Introduction

Having been called a “Truth Machine” (Casey & Vigna, 2018), blockchain technology has been widely considered for use in applications in which a lack of trust necessitates additional trust mechanisms. In the field of accounting and reporting, blockchains have been proposed as a possible way to improve the reliability of accounting information, deter concealment, provide proof of transactions, prevent data’s loss and manipulation, ensure the traceability of transactions, and improve control over management actions (Hughes et al., 2019; Karajovic et al., 2019; Schmitz & Leoni, 2019; Fullana & Ruiz, 2021). Companies such as EY, IBM, and PwC have increasingly tested the utility of blockchains in accounting, audit, and sustainability reporting. For example, EY’s OpsChain suite supports blockchain-based invoicing, asset traceability, and tokenization, pioneering real-world implementations of triple-entry accounting (Yoana, 2024). Collaborating with partners such as Home Depot and Syniverse, IBM successfully piloted blockchain for invoice reconciliation, claiming a reduction in disputes by up to 65% and shortening resolution times from weeks to days (Dickinson, 2020). PwC has also deployed pilot projects such as a VAT fraud prevention prototype jointly with Microsoft on Azure, enabling real-time invoice registration and VAT reconciliation in multi-national chains (PWC, 2019).

The academic literature has also examined the potential of blockchain technology to support innovations such as real-time accounting, aiming to reduce the delay between transactions’ recording and verification (Goel & Mishra, 2023). This reduction in timing is seen as a way to deter practices such as earnings management (Kao & Tsay, 2023; Autore et al., 2024). Thanks to its transparency and immutability, blockchain has also been proposed as a foundation for triple-entry accounting (TEA), a concept revived by Grigg (2024) to minimize discrepancies across transaction records kept by different parties. Other studies have highlighted the potential of blockchains to strengthen Environmental, Social, and Governance (ESG) reporting through improving the reliability of sustainability data (Dario et al., 2021; Saxena et al., 2023). As perceptions of blockchain capabilities vary, a wide range of integration models have been proposed to serve different purposes.

Prior research, however, has advocated caution against placing blind trust in blockchain systems, as the mere integration of this technology into legacy processes does not automatically lead to improvements (Caldarelli, 2020a; Kumar et al., 2020; Powell et al., 2022). In real-world applications such as accounting, blockchain systems rely on external data provided by third-party technologies known as oracles. However, these oracles may not possess the same level of decentralization, transparency, or reliability as the destination blockchain, thereby limiting the effectiveness and credibility of the overall integration (Egberts, 2017; Caldarelli, 2020b). A poorly designed oracle scheme can create the false impression that on-chain data are inherently trustworthy, potentially reducing the scrutiny of auditors and inadvertently enabling earnings management (Gauthier & Brender, 2021; Autore et al., 2024). In the context of ESG reporting, for example, a manipulated oracle could be used to present fraudulent sustainability metrics (Heiss et al., 2024). Similarly, if auditors are unfamiliar with how price oracles operate, they may misclassify cryptoasset values and unjustly penalize accountants who acted in good faith. This issue, commonly referred to as the oracle problem, has received relatively limited attention in the broader blockchain literature, although some studies have examined it in domains such as supply chain management, prediction markets, and decentralized finance (Sztorc, 2017; Caldarelli et al., 2020; Caldarelli & Ellul, 2021).

In a recent study, Sargent (2022) reviewed the accounting literature and found that a significant number of papers overlooked the fact that blockchain alone cannot verify the accuracy of accounting data. Given that data’s veracity depends on oracles, this suggests that a portion of the accounting and reporting literature may have neglected both the role of oracles and the oracle problem, identifying a potential gap in the literature.

In order to investigate this hypothesis, the present study conducted a systematic literature review to investigate whether (and to what extent) academic research has addressed the design and limitations of oracle mechanisms within the accounting domain. This review also identifies which oracle implementations appear to be most appropriate for accounting purposes and highlights the accounting subfields, such as ESG reporting and TEA, where research on oracles’ integration is most advanced. Finally, this study investigates whether the omission of oracle-related limitations in prior research correlates with overly optimistic assumptions about blockchain’s applicability in accounting contexts, such as the “verification issue” identified by Sargent (2022).

This research aims to address the following questions, which are central to evaluating the trustworthiness and maturity of blockchain-based accounting and reporting systems:

• Does the academic literature on blockchain and accounting’s integration consider the roles and limitations of oracles?
• What characteristics of the literature are associated with greater attention to oracles and the oracle problem in blockchain-based accounting research?
• Under the rationale that neglecting oracles’ integration constitutes a theoretical bias, what portion of the literature exhibits such a bias?
• What types of oracles have been proposed for use in the accounting field?
• Which blockchain-based accounting integration shows the most robust or advanced research on the roles of oracles?

The remainder of this paper is organized as follows. Section 2 introduces the background to the literature and provides an overview of previous works on accounting and blockchain’s integration. Section 3 describes the methodology and variables chosen for data extraction, along with the motivation to choose them. Section 4 presents the quantitative results and discusses the observable insights and qualitative results. Section 5 discusses the overall content and elaborates on common oracle schemes in the accounting field. Section 6 concludes the paper by offering final thoughts on this study’s contributions and limitations, as well as providing insights for further research.

2. Literature Background

2.1. Blockchain, Smart Contracts, and Oracles

Detailed explanations of how blockchain technology can be integrated into accounting require a technical background on Bitcoin, Ethereum, and the characteristics and limitations of smart contracts, which is provided in Appendix A and Appendix B for simplicity. In this section, key concepts are detailed to facilitate understanding of the article’s rationale.

The academic literature refers to blockchain technology as a distributed database whose data are stored in blocks, with a consensus mechanism to manage the addition of data (Crosby et al., 2016; Z. Zheng et al., 2017). Blockchains come in various types, such as public or private, and the architecture choices influence their transparency, accessibility, immutability, and resistance to censorship (Tasca & Tessone, 2019). Blockchains allow for the safe storage of data, and, with the introduction of smart contracts, more complex operations have become possible (Szabo, 1994; Alharby & van Moorsel, 2017; Antonopoulos & Woods, 2018).

For example, the first and most well-known blockchain is Bitcoin, but its limited and complex scripting language (Bitcoin Script) restricts it mainly to simple cryptocurrency transactions. By contrast, later platforms such as Ethereum and Hyperledger support more advanced applications, leveraging high-level programming languages (e.g., Solidity for Ethereum, Java or Go for Hyperledger) that enable more complex and flexible transactions. Real-world integrations, however, such as academic records, traceability, finance, and accounting, require a third component that allows data to be transferred from the real world to the smart contract. This component is known as an oracle, which operates as a bridge between the real world and the blockchain (Al-Breiki et al., 2020; Albizri & Appelbaum, 2021). These dependencies, however, generate a theoretical conundrum: if a blockchain is transparent, decentralized, and censorship-resistant, the third-party oracle should also embody the same characteristics. If the oracle is centralized and relies on a data source that is not trustless, is not transparent, and is censorable, the benefits of the blockchain will be forfeited (Egberts, 2017; Damjan, 2018; Caldarelli, 2020b).

In the case of legacy accounting, blockchains can be ideally leveraged to guarantee the accessibility and auditability of accounting records, considering the transparency and immutability of the ledger. They can also ensure accountability in the event of misreporting by leveraging the traceability of data. However, a blockchain that supports these characteristics must be chosen, and the smart contracts operating the integration should be bug-free to ensure that the system fulfills its intended scope. Furthermore, the role of the oracle in charge of transferring accounting data to the chain is crucial: if it is not transparent, accountability is not ensured, and if it is not secure, it cannot prevent data manipulation, dramatically diminishing the credibility of accounting records stored on the chain (Rîndaşu, 2019). It is important, however, to reiterate that the limitations discussed above are not due to blockchain technology itself but to poor integration choices and designs.

This aspect, known as the oracle problem, is of great importance when proposing or evaluating integrations or studies on blockchain in accounting.

While a more technical explanation of blockchain and the oracle problem is provided in Appendix B, the background provided in this section should be sufficient to understand the rationale on which this study is based. The sections below offer an overview of how the existing literature connects blockchain technology with accounting practices.

2.2. Blockchain in Accounting

The literature supports the view that blockchain technology can significantly enhance the reliability and accuracy of financial documentation (Dai & Vasarhelyi, 2017). The openness and immutability of records when transactions are digitized (Shogenov & Mirzoyeva, 2023) is seen as a way to minimize fraud (Bonsón & Bednárová, 2019). Dyball and Seethamraju (2021) proposed the use of blockchain technology as a harmonization layer to facilitate auditor work and improve audits’ quality by providing a more reliable and clear transaction record. However, despite theoretically supporting these positive views of integration, Alex et al. (2022) highlighted a persistent gap between conceptual optimism and real-world adoption, noting the scarcity of practical case studies and operational implementations.

Given this disparity between expectations and implementation, scholarly contributions in the field have taken diverse directions. The literature on blockchain’s integration in accounting is notably heterogeneous, spanning general accounting, auditing, and specialized applications such as triple-entry accounting, ESG reporting, governance, and the evolving role of accounting professionals (Han et al., 2023; Spanò et al., 2022; Silva et al., 2022; Singh et al., 2023). The following subsections synthesize these thematic clusters to map the current state of academic research.

2.2.1. Triple-Entry Accounting

Ijiri (1986) introduced the TEA theory to measure the “momentum” of money. The concept was taken up by Grigg (2024), with the aim of leveraging cryptography to limit errors and fraud in accounting. The basic idea was that companies should not be the sole recorders of business transactions and that a third party should also keep these records. Although revolutionary, at the time the concept was proposed, it was unclear how the third entry should be recorded and managed, and by which authority. The emergence of blockchain technology highlighted that it may not be necessary for a central authority to manage a ledger if a third-party, secure, transparent, and immutable ledger is available. Researchers and practitioners then begun exploring this avenue, producing early insights. Cai (2021) performed a case study review of projects proposing blockchain-based TEA and found that, although real-world applications of TEA are scarce, the results were promising. However, important challenges must be addressed, such as the uncertainty of regulations and return on investment (Pawczuk et al., 2019).

2.2.2. Real-Time Accounting/Auditing and Continuous Auditing

As Byström (2019) argued, if market pressure causes firms to put all their business transactions on a blockchain with a permanent timestamp on each transaction, the firms’ ledgers would be instantly and openly available. This would allow anyone to aggregate firms’ transactions in real time, creating related income statements and balance sheets. Considering that auditors must perform the intensive work of preparing and harmonizing accounting data before performing an audit, if all the data have been uploaded to a blockchain, their pre-emptive work can be eased (Rooney et al., 2017). In particular, the reconciliation work is practically complete, thus reducing the chance of human mistakes (Schmitz & Leoni, 2019). Constantly uploading all data on the chain is likely to transform conventional auditing based on retrospective analysis into continuous auditing based on real-time data (EY, 2016). Other authors have also supported the idea that the real-time availability of a large quantity of data may enable AI-based predictive systems to detect anomalies and prevent errors (Han et al., 2023). There is also a shared vision that real-time uploading of accounting data will reduce the chance of manipulation and fraud ex ante if managers know that all transactions are immediately available, transparent, and immutable, as there will be no chance to alter them later (Rozario & Vasarhelyi, 2018; Sheldon, 2018). However, O’Leary (2018) argued that these integrations work only if companies record all transactions on the blockchain: if only part of the transactions are recorded, the advantage is minimal.

2.2.3. Governance, Trust, and Accountability

Schmitz and Leoni (2019) have claimed that the presence of accounting data on a public blockchain may also have a considerable impact on governance, as stakeholders would have immediate access to it. When a considerable amount of accounting data are collected on the blockchain over time, stakeholders can easily inspect historical accounting data without cumbersome procedures. The immutability of blockchain technology also guarantees that the retrieved data cannot be manipulated (Roszkowska, 2021). The use of digital signatures can help to trace the uploaded data and the actors that perform the process, thereby improving accountability and transparency (Atik & Kelten, 2021). To this end, Massaro et al. (2020) explored the use of nonfungible tokens (NFTs) deployed on blockchains to enable new forms of governance.

2.2.4. ESG Reporting

Beyond financial reporting, scholars have debated the possibility of using blockchain for non-financial disclosure. In this field, sustainability data are acquired by reporting companies from different entities along the supply chain; however, the reliability of these data is often inhomogeneous (McBurney, 2022). According to the literature, integrating blockchain into ESG reporting may address this limitation as, although it cannot guarantee the authenticity of sustainability data, digital signatures used to upload data on the chain can at least enable tracing of who is responsible for uploading the data (Spanò et al., 2022). However, optimal methods for uploading non-financial data to the blockchain and the chains that are most suited to specific data are yet to be identified.

2.2.5. Blockchain’s Adoption and Its Impact on Accounting Professions

In addition to exploring the impacts of blockchain technology on accounting and reporting methods, the literature has also investigated the direct effects of the technology on the accounting and auditing professions. Companies’ acquisition of digital assets, such as cryptocurrencies, NFTs, and inscriptions for detention, trading, or use in related metaverses within the businesses’ activity, poses a significant issue in terms of their correct registration in accounting books and, consequently, their auditing (Garanina et al., 2022; Ramassa & Leoni, 2022). Such acquisitions not only impact regulations but also require accountants and auditors to develop a new set of skills to prepare for emerging use cases. While the advent of blockchain is not expected to make accountants and auditors obsolete, there is evidence of increased complexity in these roles (Schmitz & Leoni, 2019). Those who support the idea of reduced importance for these professional roles see the power of blockchain to overcome reconciliation and guarantee the authenticity of transactions, thus significantly reducing the need for accountants and auditors (Yermack, 2017; Casey & Vigna, 2018; O’Leary, 2018). In light of these advantages, other studies have investigated barriers and facilitators to firms’ adoption of blockchains for accounting practices (Fang et al., 2023; Alkhwaldi et al., 2024; Majeed & Taha, 2024).

To summarize, the literature on blockchain’s integration in accounting is highly fragmented and conceptually diverse, spanning a wide array of reporting and assurance contexts. One stream focuses on the use of blockchain as a tool to reduce errors and manipulation in legacy systems, thereby facilitating auditing and data assurance. In such applications, oracles may serve to feed external financial or transactional data into blockchain-based audit trails.

Another key area explores blockchain-based TEA, which envisions distributed ledgers as impartial records maintained independently from transacting parties. While these systems record on-chain interactions, their integration with real-world economic events may still depend on oracle mechanisms to validate off-chain inputs.

A third perspective promotes real-time accounting, where blockchain enables the continuous publication of accounting data instead of traditional periodic reporting. In these models, the timeliness and trustworthiness of input data often depend on automated feeds and external sensors, which also serve as oracles.

In the domain of ESG reporting, blockchain has been proposed as a mechanism to enhance the traceability and standardization of sustainability-related disclosures, especially given the heterogeneity and fragmentation of ESG data. As ESG metrics often originate from external sources (e.g., supply chains, environmental sensors, third-party verifiers), these systems inherently rely on some form of oracle integration.

Some authors have further highlighted blockchain’s potential to reshape corporate governance, improving stakeholders’ access to real-time reporting and thereby influencing strategic decision-making. In this context, oracles may affect not only the timeliness but also the strategic reliability of disclosures. Finally, the literature has also examined how the adoption of blockchain will impact accounting professionals, who must adapt to new technological infrastructures and accounting principles developed in conjunction with blockchain-based systems. In this context, understanding the assurance and governance of data-input mechanisms, such as oracles, becomes increasingly relevant.

3. Methodology

3.1. Database and Article Selection Process

To answer the research questions of this study, a systematic literature review was considered necessary and sufficient for the intended scope; nevertheless, further analysis was conducted on the retrieved data. Systematic reviews are critical for synthesizing existing research, effectively identifying gaps in the literature, and establishing the state of the art within a field. Their structured methodology ensures a comprehensive and replicable analysis, which enhances reliability and supports evidence-based conclusions (Grant & Booth, 2009; Moher et al., 2009).

The research began on 18 September 2024. As it offers reliable, peer-reviewed, and high-impact sources, Scopus was identified as a suitable database for this study. The author acknowledges that the use of a single database (Scopus) may introduce selection bias, potentially under-representing technical contributions from fields such as cryptography or distributed systems. However, Scopus has progressively broadened its coverage to include many technical journals and conference proceedings from sources such as IEEE and ACM. While not exhaustive, this expansion improves Scopus’s ability to capture interdisciplinary research relevant to blockchain and accounting. To optimize article retrieval, the following research string was used:

(TITLE-ABS-KEY(blockchain) AND (TITLE-ABS-KEY(accounting) OR TITLE-ABS-KEY(reporting) OR TITLE-ABS-KEY(ESG) OR TITLE-ABS-KEY(auditing) OR TITLE-ABS-KEY(accountability)).

To ensure relevance and quality, the following criteria were applied during the screening process.

Articles were included if they were peer-reviewed journal publications; written in English; explicitly addressed blockchain applications in accounting, auditing, or reporting contexts; and had full-text availability.

Papers were excluded if they were not peer-reviewed (e.g., white papers, theses, conference posters), focused on unrelated blockchain applications (e.g., supply chain, healthcare, or voting), lacked an accessible full text, or were published in languages other than English.

These criteria were applied after initial keyword filtering and title/abstract screening, followed by a full-text review of the 182 final papers. A more detailed breakdown of the process is explained below.

The query returned 3175 results, of which 42 were removed due to not being written in English, 48 were conference titles, 72 were books, and 18 were notes. The titles and abstracts of the retrieved articles were examined to check whether they involved the use of blockchain technology for legacy accounting, auditing, and reporting purposes. Therefore, studies examining accounting and auditing for cryptocurrencies or blockchain for bugs were considered unrelated. After initially skimming the retrieved literature, 2776 articles were removed because they were unrelated, leaving a sample of 219 articles. Of these, 7 articles were unretrievable, reducing the sample size to 212. All 212 articles were downloaded and read to retrieve data required for the study. A more careful inspection revealed that 30 were unrelated, despite the initial apparent relevance according to their title and abstract. This led to a further reduction of the sample to 182 articles, all of which were related to the topic under investigation. It is essential to note that this review did not include a formal assessment of the methodological quality of the selected studies using standardized appraisal tools (e.g., CASP, MMAT, JBI). This decision aligns with the exploratory and conceptual nature of the research, which aimed to identify patterns, misconceptions, and thematic gaps rather than to compare or evaluate specific empirical results. Nonetheless, this represents a limitation that future research may address through quality-based stratification or meta-analysis of specific study types. A detailed PRISMA diagram is provided in Appendix C of this article, in order to further enhance its comprehensiveness and replicability (Page et al., 2021).

3.2. Data Extraction

The data extracted for the systematic review included article type, date, and topic, as well as other categories that were identified to meet the purposes of this study. As explained in (Tasca & Tessone, 2019; Caldarelli, 2024), since blockchains are not univocal, considering them as such can lead to biased expectations regarding the technology’s potential. Therefore, the articles were inspected and divided into those that considered blockchain as a univocal technology, those that did not, and those that made a deep distinction between different chains. For the same reason, empirical papers were also examined to determine whether the investigated blockchain was explicated, as the related findings are most likely not extendable to other chains.

The primary focus of this study, however, was to assess whether the academic literature on the use of blockchains in accounting and reporting has explicitly or implicitly addressed the roles of oracles and the oracle problem. Given the ambiguity and overlapping meanings of the term “oracle” (e.g., referring to the Oracle Corporation, oracles in classical history, oracles as a design pattern in computer science), a simple keyword search was deemed insufficient.

To ensure consistency, we manually reviewed the full text of each article and applied a three-tier classification.

Direct mention: The article explicitly refers to blockchain oracles, the oracle problem, or similar terminology (e.g., “oracle paradox” or “oracle mechanism”).

Indirect mention: The article does not use the term “oracle,” but refers to analogous concerns such as data input reliability; the use of sensors, RFID, or external data feeds; and phrases like “data cannot be verified” or “reliance on external information.”

No mention: The article does not discuss or imply any reference to oracles, data feeds, or the limitations of real-world data input into blockchain systems.

This classification approach enabled more specific identification of how the oracle problem has been addressed or overlooked in the literature, beyond simple terminological matches.

As Caldarelli (2020a) speculated, articles mentioning oracles and the oracle problem are less likely to include overexpectations about blockchain’s potential; therefore, this aspect was also investigated. Overexpectations (as discussed in

Table A1. Blockchain features, limitations, overexpectations, and research strings used in the study (author’s elaboration).

Blockchain Features and Limitations	Overexpectations	Search String/Marker	Reference
Blockchain decentralization is guaranteed by miners or stakers who compete with each other, investing in mining equipment or stakes in return for cryptocurrencies. Multiple nodes do not imply decentralization and do not verify arbitrary data.	Blockchain systems are inherently decentralized and trustworthy simply because they involve multiple nodes.	“multiple nodes ensure data reliability” “data is verified by distributed nodes”	(Antonopoulos, 2016, 2017; Gates, 2017; Antonopoulos & Woods, 2018)
The Bitcoin ledger keeps track of cryptocurrency owners by adding updated data to the ledger; it does not directly trace them around the network. Therefore, it cannot directly trace real-world assets.	Blockchain can trace individuals or real-world assets across the network automatically.	“blockchain can trace real-world assets” “ledger provides full asset traceability”	(Brühl, 2017; Kumar et al., 2020; Caldarelli et al., 2023)
To implement blockchains in applications aside from the simple exchange of currencies, smart contracts need to be implemented. These, like any computer program, may contain bugs and do not imply automation.	Smart contracts guarantee trustless and error-free automation.	“self-executing and self-enforcing contracts” “blockchain enables automatic processes.”	(Frankenreiter, 2019; Harris, 2019; Tasca & Tessone, 2019; Mühlberger et al., 2020)
For applications that require real-world data, oracles are introduced, whose security is unrelated to that of the chain. Therefore, a direct reduction in intermediaries is not achieved through the implementation of blockchain, as new ones (oracles) are introduced.	Blockchain eliminates all intermediaries.	“blockchain removes the need for third parties” “blockchain provides full decentralization across layers”	(Buck, 2017; Egberts, 2017; Caldarelli, 2020b; HacKen, 2020; B. Liu et al., 2021)
Blockchains store a limited quantity of data; for Bitcoin, a 32-byte hash was already considered excessive. Although other chains allow a higher quantity of data, the associated price is considerably higher.	Blockchain can store all kinds of documents and data directly on-chain.	“all accounting data is saved on-chain” “immutable storage of all data on-chain”	(bchworldorder, 2018; Strehle & Steinmetz, 2020; BitMex-Research, 2022)

) may refer to the idea that blockchains ensure the truthfulness of data, automation capabilities, or real-world integration without considering the roles or limitations of oracles. A recent article by Sargent (2022), for example, showed that many papers published in the accounting field are overly optimistic due to misconceptions about blockchain consensus. Therefore, it is important to investigate the nature of these overexpectations and determine whether other types of bias exist. In our coding structure, we considered articles to include overexpectations if they included one or more of the factors listed in Appendix B, Table A1.

Another aspect to clarify is that, although the presence of overexpectations in a retrieved paper indicates a theoretical limitation of the research, it does not question the quality of the research itself; it can be argued that such overexpectations may be due to biased data from prior or early reviews or information provided by interviewed experts. Blockchain technology is a complex subject and finding official and reliable information can be challenging, especially in the early stages.

A concept-centric coding approach (Webster & Watson, 2002) was applied when analyzing the final set of studies, using “oracles” and the “oracle problem” as a pivotal concept (Miles & Huberman, 1994) to structure the interpretation. This allowed one to systematically evaluate how each paper addresses the issue of real-world data reliability in blockchain accounting systems. This technique follows standard practices in qualitative content analysis for the synthesis of literature, where recurring constructs are used as thematic anchors for classification (Miles & Huberman, 1994; Tranfield et al., 2003). Basically, once the data are extracted from the sample, they are reinspected considering oracles as a pivot. For example, it was examined whether papers that include overexpectations consider oracles, which accounting implementations tend to consider oracles, whether papers that consider oracles are more empirical or theoretical, and so on.

To summarize, the classification process was structured as follows.

First, standard variables for the systematic literature review (SLR) were extracted, such as the type of publication, year, and publisher. Second, the type of research was inspected to distinguish whether it was theoretical or empirical, whether it utilized qualitative or quantitative data, and what type of data was leveraged. Third, the consideration of oracles and the oracle problem was inspected through direct or indirect references. Subsequently, the literature background was reviewed to identify any significant differences among chains that could affect the benefits of blockchain’s integration. It was then determined whether the analysis focused on one or more specific approaches to blockchain’s integration in accounting, and, finally, the oracle coding was utilized as a pivotal concept to analyze the extracted data.

To identify overexpectations in the reviewed literature, known limitations of blockchains were mapped against common misinterpretations (Table A1). For each limitation, an indicator string was formulated, and a textual marker was designed to indicate whether a given overexpectation appeared in a paper. This approach enabled the systematic tracing of conceptual biases in the literature using a transparent set of text-mining criteria.

Figure 1 shows the study design, and

Table 1. Analytical framework of the review.

Category	Definition	Illustrative Keywords/Coding Examples
Article Type	Classifies the methodological nature of the study (e.g., theoretical, empirical, review)	Theoretical; empirical; qualitative study; quantitative analysis; systematic review; case study
Blockchain Literature Breadth	Indicates whether the article treats blockchain as a singular, generic concept or distinguishes between different types of blockchain systems	General: generalized use without specifying type; Moderate: public/private, permissioned, etc.; Extensive: differentiation between specific chains and implementations
Blockchain Specification	Captures whether the article refers to a specific blockchain platform, such as Ethereum, Hyperledger, or private blockchains, for accounting or reporting purposes	Mentions Ethereum, Hyperledger, Tezos, etc., in an applied context; not applicable when the paper is a review.
Oracle Mention	Describes whether and how the article discusses the concept of oracles or the oracle problem	Direct mention: “oracle problem,” “oracle mechanism”; Indirect: “sensors”, “RFID”, “unverifiable source”
Overexpectations Present	Identifies whether the article includes overstated claims about blockchain’s capabilities (based on the predefined expectations listed in Appendix B Table A1)	Immutable truth; blockchain eliminates fraud; no need for auditors; fully automated trust; no human intervention
Main Topics Discussed	Classifies the dominant themes of the paper within the accounting and reporting field	ESG reporting; triple-entry accounting; real-time accounting; auditing; financial reporting; governance impact

Note: variables such as title, author, and year are omitted because they are self-explanatory.

summarizes the analytical framework of the review.

4. Findings

Through direct observation of the overall sample, the first research question of this study can already be answered: it emerged that 124 (67%) articles did not mention oracles at all, while 42 (24%) considered them indirectly, and only 16 (9%) considered them directly. Similarly, 138 (75%) articles did not mention the oracle problem, while 39 (22%) mentioned it indirectly, and only 5 (3%) discussed it directly (Figure 2).

Oracles and the oracle problem were then used as pivotal concepts to analyze the retrieved articles. Inspecting the change in the number of mentions of oracle concepts with respect to the publication year (Figure 3), a positive pattern emerges; namely, a steady increase in the number of papers mentioning both oracles and the oracle problem can be observed, as well as a sharp decrease in papers not considering both. This is a clear sign that consideration of this subject in the literature is slowly increasing.

In order to answer the second research question of this study, the relationships between mentioning oracle concepts (i.e., oracle attention) and the methodological approach, blockchain literature breadth, and blockchain analysis were examined. The relationship between oracle attention and methodological approach (Figure 4) highlights that practical proposals mostly took the roles of oracles and the oracle problem into consideration (83%), providing insights into the communication channels used to transfer data into blockchains. Other types of research, including theoretical research, reviews, and qualitative studies, were found to only consider oracles at rates of 47%, 32%, and 23%, respectively. Finally, empirical research using quantitative data showed almost no consideration of the role of oracles, indicating a possible gap in the literature.

The breadth of a study in the blockchain literature also influences the consideration of oracles. Articles with univocal descriptions of blockchains were found to rarely consider oracles (26%), whereas those with extensive descriptions of different blockchain types were more likely (62%) to discuss oracles (Figure 5). Additionally, articles that analyzed a specific blockchain type were most likely (68%) to include a section discussing the roles of oracles (Figure 6), regardless of the type.

Interesting results were also obtained when analyzing the relationship between topic and consideration of oracles.

Table 2. Consideration of oracles and the oracle problem according to study theme.

Theme	Mentioned Oracle	Mentioned Oracle Problem	Mentioned Both	None	Total
General A&A	17	12	17	63	109
ESG Reporting	9	0	9	7	25
Governance and Trust	1	3	0	6	10
Accounting Professions	3	7	5	20	35
Adoption and Acceptance	0	3	1	22	26
Triple-Entry Accounting	7	3	0	18	28
Real-Time Accounting	4	2	0	19	25

shows that a consistent proportion of papers (46) on general accounting and auditing considered oracles and the oracle problem. Other sectors in which oracles have been investigated include ESG reporting (18 occurrences), accounting professions (15), TEA (10), and real-time accounting (4).

The above cross-analysis provides an answer to the second research question: it emerges that the accounting literature taking oracles into consideration is mainly of an empirical nature, focused on specific chains, and primarily concerns general accounting and auditing implementations, as well as ESG reporting.

The analysis now shifts to the answer of the third research question. This question can be partly addressed through quantitative analysis examining the relationship between the presence of overexpectations and the consideration of oracles. As papers are published after reviews and editorial checks, it can be considered that mistakes and conceptual flaws are filtered in the review phase. In fact, most of the papers displayed no overexpectations or misconceptions. However, it can be noted that the studies including overexpectations generally did not consider oracles and the oracle problem.

Figure 7 shows that the percentage of articles containing overexpectations dropped significantly, from 25% of the entire sample to 6% of the papers that considered oracles and the oracle problem. In particular, the graph shows that no research considering the oracle problem included any overexpectation about blockchain’s potential. Therefore, and partly in response to the third research question, it can be argued that studies examining the roles of oracles and their limitations are less likely to include common misconceptions and overexpectations regarding blockchain.

To fully address the third research question and offer insights into the overexpectations commonly found in the accounting literature, a qualitative analysis of the retrieved papers is provided in the following.

4.1. The Oracle Problem in Accounting and Auditing

Many authors have warned about potential issues arising from the integration of blockchain within the broader accounting and auditing sector. Gauthier and Brender (2021) claimed that “it is not appropriate for auditors to assume that… information recorded in a blockchain can be relied on with no prior testing.” They stated that it takes time to change auditing standards, and they tend to change only when incidents challenge the work of auditors.

Additionally, Autore et al. (2024) stated that false beliefs regarding the improved reliability provided by blockchain technology actually facilitated earnings management, meaning that it was more likely to occur in companies that integrated this technology. The concept of truth in the context of blockchains for those with a limited background in computer science is, in fact, counterintuitive. All the data on the blockchain are indeed “TRUE,” in the sense that they have been added in compliance with specific conditions; however, information evaluated as “TRUE” is not necessarily accurate or reliable. Nothing prevents untrue information from being written on the blockchain, as long as the condition for writing this information is verified (Powell et al., 2022). The blockchain was initially meant to prevent double-spending and provide time certainty for transactions; however, no references are available on the intention of using this tool to facilitate veracity of information, nor does it support this specific purpose.

According to Goel and Mishra (2023), blockchain is a “canonical source of truth.” Y. Tang (2021) stated that information on chains is “authentic and cannot be changed at will,” and R. Zheng (2021) and Matringe and Power (2024) have claimed that blockchain encryption mechanisms ensure the reliability and authenticity of accounting information: “algorithm as truth of fact.” Notably, a study that included an interview with an external expert contained overstatements regarding the truthfulness of the data. The expert’s statement that “transactions recorded would be mostly authentic” (Abdennadher et al., 2022) confirms concerns raised in previous research (Caldarelli, 2024) that the quality of the experts consulted in these studies needs to be verified more carefully, or their statements should be more carefully assessed.

Regarding the concept of truthfulness of data on the chain, Sargent (2022) argued that “the potential disconnect between digital and real-world transactions can create potentially misleading illusions-of-truth.” Essentially, the article explained that consensus does not mean verification, showing that 46% of the articles examined rely on this misconception. Extending the critique of Sargent (2022), Coyne and McMickle (2017) stated that “the maintainers of these blockchains know nothing about the true validity of the transaction… the agreement between the two parties resulted in the asset transfer. They only know whether the transaction uses unspent inputs and is digitally signed.” However, a consistent stream of literature supports the truthfulness of accounting data on blockchains by relying on the consensus mechanism. R. Liu (2020) stated that it is almost impossible for accountants to commit fraud, because, to do so, they must record false data on the blockchain, broadcast this to all nodes, and obtain consensus. Zhong and Fan (2021) added that “if a node has false information, all the information reported on this node will be rejected by other nodes.” Although this concept is also supported in Yang (2020), Fang et al. (2023), Li (2023), and Johri et al. (2022), the nodes do not verify the truthfulness of the data uploaded by other nodes that do not pertain to the consensus mechanism. Therefore, as Lobanchykova et al. (2024) explained, although we can, to a certain extent, exclude manipulation ex post (Wang et al., 2020), we cannot be certain of the historical truth of accounting records.

Another stream of research proposes that the integration of accounting practices relies on smart contracts and the automation capabilities of blockchains; capabilities that they arguably do not possess. As specified by Fang et al. (2023), implementing blockchains for auditing through smart contracts will increase the auditors’ work, as they must also verify the reliability of these contracts. The authors in Thies et al. (2023), Dai and Vasarhelyi (2017), Alrfai et al. (2024), and Zhao et al. (2022) envisioned the ability to monitor transactions and predict eventual mistakes or fraud using blockchains and smart contracts. Although this is possible through the use of certain oracles connected to AI tools that process blockchain data, fully transparent or fraud-free mechanisms cannot be guaranteed. Again, automating accounting actions based on the predetermined rules proposed in Bora et al. (2021) is not possible with blockchains and smart contracts alone, as they are not connected to real-world data. Described in Karim (2024) as a “first- and last-mile problem”, the author argued that blockchains cannot verify the truthfulness of data acquired through a third party, and, similarly, an auditor cannot be certain of data retrieved on the blockchain (Alles & Gray, 2023). In addition, the “track-and-trace” capability of blockchain, proposed in Karajovic et al. (2019), Subramoniam et al. (2022), and Majeed and Taha (2024) for continuous auditing, is also infeasible for the abovementioned reasons.

Additional studies support an optimized auditing function with blockchains through a reduction in intermediaries, which should alleviate or eliminate the work of auditors (Abu Afifa et al., 2023; Yu et al., 2018; He, 2021; Lindawati et al., 2023). However, Tan and Low (2019) argued that it “is inconclusive that using blockchain-based accounting information systems (AISs) will automatically produce financial statements that are true and fair, and hence the fear that the audit industry will be disrupted is unfounded.” As extensively explained in previous research (Gaggioli et al., 2019; Eskandari et al., 2021), due to the reliance of blockchain technology on oracles for external data, we cannot attain a reduction in but, rather, a substitution of intermediaries. Despite mistrust in some financial institutions, there is no reason to believe that third-party blockchain oracles are trustworthy and reliable intermediaries. This substitution of intermediaries will de facto not alleviate the work of auditors, who must still verify the reliability of third-party oracles and the authenticity of the transmitted data. Finally, the last stream of research bases its idea of integration on the possibility of registering all accounting transactions in the chain (R. Zheng, 2021; Byström, 2019). While possible in theory, this is undesirable because, even if we ignore the high cost of fees, as blockchain is freely available to the public, due to limited space, registering accounting data on the chain will significantly limit the usability of blockchain technology for other use cases and will require nodes to maintain the accounting data at the node’s own cost. Therefore, as has happened in the past for non-standard transactions, this is unlikely to be permitted (Mercanti et al., 2018; BitMex-Research, 2022). Based on these false beliefs and limitations, Coyne and McMickle (2017) argued that blockchains cannot serve accounting purposes. However, the author of this study does not share this pessimistic vision. The problem is determining how best to integrate blockchains for the right purpose with the right oracle.

Table 3. Overexpectations and their relation to the oracle problem in blockchain-based accounting.

Overexpectations in Blockchain-Based Accounting	References	Clarification	References
The blockchain encryption mechanism ensures the reliability and authenticity of accounting information.	(Matringe & Power, 2024; Y. Tang, 2021; R. Zheng, 2021)	Blockchain guarantees immutability to a certain extent but not truthfulness. Oracles can verify truthfulness only if a specific design is implemented.	(Gauthier & Brender, 2021; Autore et al., 2024; Lobanchykova et al., 2024; Al-Breiki et al., 2020)
If a node has false information, all the information reported on this node will be rejected by other nodes.	(Zhong & Fan, 2021; Yang, 2020; Fang et al., 2023; Li, 2023; Johri et al., 2022)	Nodes are unaware of the true validity of the transaction; they simply verify whether the input is unspent. Arbitrary data inserted by oracles are not verified for validity.	(Sargent, 2022; Coyne & McMickle, 2017; Damjan, 2018; Caldarelli, 2020b)
Smart contracts can automatically monitor transactions and predict fraud.	(Thies et al., 2023; Dai & Vasarhelyi, 2017; Alrfai et al., 2024; Zhao et al., 2022)	Smart contracts cannot provide more automation than any other regular computer program. Oracles can perform off-chain computations, but they are not infallible.	(Antonopoulos & Woods, 2018; Song, 2018; Frankenreiter, 2019; Mühlberger et al., 2020; Caldarelli, 2021)
Blockchain can reduce intermediaries and eliminate the work of auditors.	(Abu Afifa et al., 2023; Yu et al., 2018; He, 2021; Lindawati et al., 2023)	Auditors are essential for evaluating the reliability of third-party oracles and cannot be eliminated.	(Alles & Gray, 2023; Tan & Low, 2019; Sheldon, 2021a, 2021b; Fang et al., 2023)
Blockchains can be leveraged as a decentralized database for accounting transactions.	(R. Zheng, 2021; Byström, 2019)	Blockchains have extremely limited data storage. Storing large quantities of data can be expensive and is often opposed.	(Mercanti et al., 2018; BitMex-Research, 2022; Bistarelli et al., 2019)

provides a breakdown of the overexpectations in blockchain-based accounting, finally answering the third research question. The following paragraphs address the fourth research question by qualitatively examining the oracle solutions proposed for different accounting applications.

4.2. Oracle Ecosystems in Accounting and Auditing

Few studies have investigated the integration of blockchains in practical terms, which narrows the available studies describing oracle schemes. As for TEA, two examples of possible oracle implementations come from Craig Wright, a controversial figure claiming to be the creator of Bitcoin. Pan et al. (2023) proposed linking wallets with identity and registering invoices on Bitcoin, such that auditors can easily verify the correctness of the invoices and their provenance. Sunde and Wright (2023) extended this concept and proposed a “fingerprint” with a digital signature that should be associated with every double-entry transaction and copied into a third ledger. The third ledger then has both the fingerprint of the related parties’ books and their signatures for auditing purposes; in the author’s words, “This way, identity can be verified without relying on a single oracle or intermediary.” Kao and Tsay (2023) proposed a TEA system in which both parties involved in a transaction have to sign a smart contract, which is then verified by a “miner” who stores the transaction on the chain for auditor inspection. In this context, the certainty of the transaction is guaranteed by both the sender’s and receiver’s signatures, and the timestamp does not allow for earnings management; in particular, the buyers and sellers are the oracles themselves. Other studies on TEA, such as those of Faccia et al. (2020) and Maiti et al. (2021), have mentioned incorporating a mechanism that places data on-chain (either manually or with APIs); however, they did not further elaborate on these mechanisms, and, therefore, no speculation on how such an approach can be replicated in other systems is possible.

In a well-cited article, Rozario and Thomas (2019) discussed the potential of blockchain to enable continuous audits. The basic idea is to use blockchains as an immutable ledger with data of traceable origin to improve accountability. Furthermore, with IoT connected to blockchains, much more non-financial information can be made available to auditors for a wide range of purposes. Barandi et al. (2020) specified that information and resources should be shared directly between peers, rather than through a central node. McCallig et al. (2019) extended this idea to continuous auditing but focused on data certainty. Their proposal relies on multi-party security, which scatters data among customers, and applies this technique to the blockchain with the aim of “emulating a trusted party.” However, communication channels still represent an unresolved challenge.

Concerning specific applications in accounting, Kafshdar Goharshady et al. (2018) focused on credit reporting and elaborated on identity management to allow access to data in blockchains. The idea is that users create a record with their private key and a “fingerprint” that constitutes a unique identifier, to which lending institutions add credit risk data. Other institutions then require keys from the user (not the lending company) to access the record. In this case, the lending institution plays the role of an oracle by registering the user’s credit risk data. Sarwar et al. (2021) proposed data vaults for a trial balance, where each line is hashed and stored in a cryptographically secure place. This helps to verify whether the trial balance registered in the AIS was manipulated. As ownership and responsibility for the data remain in the hands of the company, the company is the oracle. With a greater focus on taxes, Lazarov et al. (2022) proposed a system for tax reporting in cross-border transactions. For this system to work, both nationalities involved in a transaction must sign a copy of the same transaction with different identifiers. In this way, for each transaction, there are two copies: one with one country’s identifier and another with the other country’s identifier. A lost hashed copy on either side indicates manipulation or misreporting. In this case, the authorities are the oracles.

More oriented to a general integration of blockchain in accounting, J. Wu et al. (2019) proposed a system of smart contracts to link economic and accounting events with accounting reports. The proposed method to gather real-world data combines IoT and GPS to track goods from buyers’ and sellers’ warehouses. No additional explanation is given of how they should work, but the authors stated that “the IoT serves as a data collector and recorder immune to mistakes and fraud, which ensures the faithful and prompt upload of inventory information to blockchain.”

Mingming (2020) described a blockchain integration idea that uses an I/O interface to transfer data to the chain, which is thus securely stored to prevent manipulation. However, little information on the selected I/O interface was provided. Anwar et al. (2019) bypassed this issue by assuming that transactions occur directly on the blockchain, and they suggested that nodes use the company’s name such that the public key is recognizable in the auditing procedure. Ingle et al. (2019) proposed a network of companies, where every company represents a node. Information on the chain is inserted upon consensus, although the consensus mechanism was not clarified.

Although Sheldon (2021a, 2021b) is the only author to discuss oracles within the accounting profession, he did not propose a specific oracle scheme. Instead, Sheldon envisions auditors as oracles, arguing that oracles should be treated as service organizations under auditing standards, as they perform critical data-processing tasks that affect the financial reporting and control systems of the entities using them. He proposed control objectives for auditors to ensure the integrity of data used by smart contracts and identified open questions and challenges for accounting professionals, including defining what constitutes an appropriate consensus among multiple oracles and how to handle the risks of compromised data sources. The author invited auditing professionals to consider and address the risks associated with oracles, as firms using blockchain technology must ensure that oracles providing data to smart contracts are reliable and have appropriate controls in place. Despite Sheldon’s brilliant contribution in 2021, none of the subsequent articles concerning the adoption of blockchains in accounting or their impact on the accounting profession have referred to this crucial aspect.

Table 4. Proposed oracle ecosystems in accounting and auditing.

Oracle Mechanism	Accounting Application	Reference
Buyers and sellers sign the transaction and take responsibility for the veracity of data.	TEA	(Kao & Tsay, 2023; Pan et al., 2023)
A fingerprint is associated with the transactions in the double-entry ledger, and both fingerprints are inserted into the third-entry ledger.	TEA, general accounting, and auditing	(Sunde & Wright, 2023; Kafshdar Goharshady et al., 2018)
Use IoT to put data on the chain.	General accounting and auditing, real-time accounting	(Faccia et al., 2020, 2021; Maiti et al., 2021; J. Wu et al., 2019; Mingming, 2020)
An authority signs the transaction and takes responsibility for its veracity.	General accounting and auditing, credit risk reporting, tax reporting	(Rozario & Thomas, 2019; Kafshdar Goharshady et al., 2018; Sarwar et al., 2021; Anwar et al., 2019)
Data are scattered among peers, and multi-party security is used to mimic a trusted party.	Real-time accounting	(McCallig et al., 2019)
Auditors are oracles.	Accounting professions	(Sheldon, 2021a, 2021b)

summarizes the proposed oracle designs for use in the context of accounting and auditing.

4.3. Oracle Ecosystems in ESG Reporting

While some studies (Zhang & Zhu, 2022) have envisioned the simple use of blockchain for higher ESG data reliability, other studies have investigated how to transfer such data onto the chain securely. A group of studies conducted by the same investigation team emphasizes the persistent challenge of guaranteeing that the data collected prior to uploading onto the chain are authentic, claiming that little research has been carried out in this direction (Chen et al., 2024; W. Wu et al., 2022a, 2022b). Similar to L. Liu et al. (2024), W. Wu et al. (2022b) proposed a system of token-based incentives to motivate companies to increase their ESG disclosure. The authors proposed combining three variables, disclosure, throughput, and authenticity, to determine the number of tokens and the value of the distribution among companies that have increased their disclosure. The intervals for the disclosure and throughput variables were capped to avoid excess data, which could result in (1) redundancy that will reduce its utility and (2) congestion on the blockchain with data of uncertain utility. Therefore, the authenticity variable was given a greater weight. W. Wu et al. (2022a) supported data authenticity and proposed a multi-layer system for collecting and transferring ESG data in a chain. The first layer, intended to measure the key performance indicators for ESG disclosure, as proposed in (Seidenfad et al., 2024) and (Dai et al., 2019), comprises meters and sensors to monitor electricity consumption, water consumption, gas emissions, and waste. The second interoperation layer provides support for data transmission. The data collected by the meters and verified in terms of space and time are transmitted through network communication protocols (e.g., Bluetooth, 4G/5G, and Wi-Fi) in batches to the blockchain layer. The envisioned blockchain is a consortium chain that guarantees the inability of a single entity to manipulate data and a certain degree of agreement in the data upload. In addition, integrated Application Programming Interfaces (APIs) should allow for the inward and outward transmission of collected data. The fourth layer is an interface that allows data to be collected by stakeholders.

Chen et al. (2024) elaborated on ways to ensure the authenticity of data and proposed an event-based authenticity algorithm. This system is articulated in three phases: the first phase involves evaluating the responsiveness and reliability of IoTs; the second phase involves collecting data on different events distinguished by location; and the last phase involves analyzing the probability of correlations among the events and data collected to further assess their reliability. The data are then re-evaluated by comparing them with a global index that is leveraged to identify potentially fake or unreliable data.

Using a different approach to guarantee the authenticity of data, Heiss et al. (2024) proposed an attestation service for carbon emissions accounting and reporting on the blockchain. The article explained that it is unfeasible to monitor, report, and verify carbon emissions on-chain due to blockchain’s privacy and scalability limitations, which clash with the privacy, quantity, and computation required for these types of data. However, the blockchain’s characteristics can be leveraged if complex computational activities are performed off-chain. In their design, the system works as follows. In the monitoring phase, the carbon footprint data are obtained through attestation from the sensors and suppliers. These attestations ensure that confidential inputs originate from the expected data source. In the reporting phase, the attestations are verified, and the emissions are calculated. Then, a Zk proof is generated and sent to the blockchain contract. Finally, the contract inspects the Zk proof and evaluates whether the product’s carbon footprint has been correctly assessed, in compliance with the accounting standards. This last phase also verifies whether only the data already checked by auditors are used for the parameters. Q. Tang and Tang (2019) and Luo et al. (2024) supported a different approach for sustainability reporting, the underlying idea of which is to shift voluntary emissions disclosures from a centralized to a decentralized database. The idea is to improve the security ex post rather than ex ante and facilitate data computation through the accessibility of DLTs. Using this method, the ex post responsibility for data’s authenticity does not shift to the blockchain ecosystem but remains with the company responsible for the disclosure. Additionally, Luo et al. (2024) proposed that requiring authorized stakeholders to put data on the chain with a digital signature and timestamp will facilitate accountability in the case of fraudulent data. In this sense, while blockchains will not prevent false data uploads, they can facilitate the detection of accountable persons and, to a certain extent, disincentivize malpractices.

Table 5. Proposed oracles for ESG reporting.

Oracle Mechanism	References
System of IoTs, continuous data gathering, and multiple checks with complex algorithms to ensure IoTs’ reliability, eliminate outliers, and ensure data veracity.	(Chen et al., 2024; W. Wu et al., 2022a, 2022b)
An attestation service guarantees that non-financial data come from the designated source.	(Heiss et al., 2024)
Companies or authorized stakeholders are oracles and retain full responsibility for the uploaded data.	(Q. Tang & Tang, 2019; Luo et al., 2024)

provides an overview of the oracle solutions proposed for ESG reporting, while

Table 6. Key findings of this research.

Research Question	Answer
Does the academic literature on blockchain and accounting’s integration consider the roles and limitations of oracles?	Of the papers in the final sample, 32% included content on oracles, and 17% mentioned the limitations of oracles. However, only 12% provided information on how to design oracles for accounting purposes.
What characteristics of the literature are associated with greater attention to oracles and the oracle problem in blockchain-based accounting research?	The accounting literature on oracles is primarily empirical, focused on specific chains, and addresses topics such as general accounting and auditing implementations and ESG reporting.
Under the rationale that neglecting the integration of an oracle constitutes a theoretical bias, what portion of the literature exhibits such a bias?	Of the total sample, 25% included overexpectations about blockchain’s potential; however, of the articles that mentioned the oracle problem, only 6% included overexpectations.
What types of oracles are proposed in the accounting field?	The oracle role is expected to be performed by the following: A designated authority/stakeholder; Buyer and seller; A combination of nodes through multi-party authentication; An attestation service; An IoT; A system of IoTs; A system of algorithms to guarantee the authenticity of data.
Which blockchain-based accounting integration shows more robust or advanced research on the role of oracles?	The ESG reporting literature shows advanced oracle mechanisms, although only in a few papers. Practical implementations are considered feasible. Oracles have not been studied from the viewpoint of accounting professionals, but they should be prepared to audit price oracles.

summarizes the key findings of this study according to the research questions.

5. Discussion

This systematic review highlights significant gaps and biases in how the accounting and ESG reporting literature has addressed blockchain oracles and the associated oracle problem. This section examines the study’s theoretical contributions and outlines implications for accounting and reporting practices.

5.1. Theoretical Implications of Oracle Mentions in the Accounting Literature

Although the findings of this review indicated that oracles were considered in just over 30% of the analyzed studies, this figure should not be interpreted as negligible. A 2020 study (Caldarelli, 2020a), which covered a wide range of research fields, found that oracles were addressed in only 18% of academic publications at the time and largely within the domain of decentralized finance. While no specific benchmark exists for the accounting and reporting literature, the observed increase to over 30% in recent years suggests a growing awareness and uptake of oracle-related considerations within these fields.

Building on the work of Sargent (2022), this study hypothesized that papers failing to mention oracles would be more likely to include overexpectations or conceptual biases regarding the potential of blockchains. The findings supported this hypothesis, as only 6% of the papers discussing oracles exhibited such overexpectations, indicating that such biases are predominantly found in studies that overlook the oracle layer. Further insights emerge when comparing this review to Sargent’s earlier study. In 2021, Sargent found that 46% of published papers contained the specific bias of attributing the ability to independently verify external data to blockchains. In contrast, this review, which draws on a substantially larger and more recent sample and examined a broader range of overexpectations, revealed a lower bias rate of 25%. This decline suggests a general improvement in the quality of the blockchain-related accounting literature, possibly linked to growing awareness of the oracle problem.

Regarding the types of papers that address oracles and the oracle problem, the accounting literature largely mirrors trends observed in other disciplines. Empirical studies, such as those carried out by Chen et al. (2024) and Sarwar et al. (2021), tend to propose specific oracle solutions or extensions to existing implementations. In contrast, the few theoretical contributions within the accounting and reporting literature, such as those of Coyne and McMickle (2017) and Akter et al. (2024), primarily aimed to raise awareness of the oracle issue rather than offering formalized design frameworks.

As a result, the accounting literature still lacks dedicated theoretical models tailored to oracles’ integration in reporting contexts. This contrasts with other fields, such as finance (e.g., Eskandari et al., 2021) and law (e.g., Damjan, 2018), where more rigorous theoretical explorations have emerged. Given the epistemological and multi-disciplinary nature of the oracle problem, as emphasized in prior work (Egberts, 2017; Caldarelli, 2020b), there is a clear need for accounting scholars to establish a stronger conceptual foundation in order to guide both practice and future empirical research.

5.2. Theoretical Implications of Oracle Designs for Reporting Purposes

The analysis of the reviewed literature revealed a recurring oracle design proposed for both financial and non-financial reporting contexts, as illustrated in Figure 8. The design typically begins with the identification of a primary data source, which may consist of either traditional databases (for financial data) or IoT devices (for ESG metrics and other non-financial data) (Kao & Tsay, 2023; Pan et al., 2023; Sunde & Wright, 2023; Dai et al., 2019). To ensure the reliability of the source data, responsibility is generally assigned either to a trusted authority or to the transaction counterparties. These actors are tasked with validating and signing the data, before they are transmitted to the blockchain through an attestation service, a mechanism intended to preserve data’s integrity throughout the process (Rozario & Thomas, 2019; Kafshdar Goharshady et al., 2018; Sarwar et al., 2021). The validated data are then stored on a private blockchain, which is chosen primarily for its ability to ensure access control and operational flexibility in enterprise contexts (W. Wu et al., 2022a; Chen et al., 2024).

Although technically feasible, this oracle configuration raises several theoretical concerns related to trust, decentralization, and accountability. First, the reliability of the primary data source has been frequently questioned in the literature; particularly when IoT devices are involved, due to the potential for sensor malfunctions, calibration issues, or environmental manipulation (Powell et al., 2022). Second, delegating data validation to a single authority or to transaction parties introduces risks of collusion, bias, or external influence, thereby undermining the decentralized trust model that blockchain technologies aim to support (Egberts, 2017; Sztorc, 2017). While McCallig et al. (2019) advocated for multi-party validation to counteract centralization risks, this approach presumes the availability of diverse and independent authorities, an assumption that may not hold in many real-world scenarios. Moreover, signature-based methods intended to ensure authenticity and non-repudiation face difficulties in reliably linking digital credentials to accountable real-world entities, especially in global or cross-jurisdictional applications (Douceur, 2002).

Attestation services, which are frequently mentioned as intermediaries responsible for ensuring data’s integrity during transmission to the blockchain, appear to be a practical choice to prevent tampering or alteration in the data flow (Dai & Vasarhelyi, 2017; Abdulla et al., 2022; Garanina et al., 2022). These services add a layer of security by verifying that data remain unmodified between collection and on-chain registration. However, some advanced cryptographic solutions proposed in the literature such as the use of zero-knowledge (ZK) proofs, as discussed by Heiss et al. (2024), raise further concerns regarding scalability. While ZK proofs offer a powerful means of preserving privacy and integrity, their application in accounting contexts may prove cost-prohibitive. Given the high volume and frequency of financial transactions, the computational overhead associated with these techniques could significantly limit their practical adoption in real-world enterprise environments.

Regarding the choice of blockchain infrastructure, most of the reviewed papers identified private (permissioned) blockchains as the most viable solution for reporting applications. These systems allow for greater control over access and governance, aligning with the needs of enterprises and regulatory environments (Z. Zheng et al., 2017; Androulaki et al., 2018). However, as highlighted in the literature, permissioned chains also raise concerns about transparency and centralization, as their consensus mechanisms are often less publicly auditable and may be susceptible to collusion or single points of failure (Yermack, 2017; Rauchs et al., 2018). A minority of studies considered public blockchains such as Bitcoin and Ethereum as potential alternatives, but their limited data storage capabilities restrict them to roles such as anchoring hashed data or digital signatures, rather than storing full accounting records.

Looking ahead, the potential introduction of central bank digital currencies (CBDCs) has been noted in the literature as a transformative development (Augusto et al., 2023; Grigg, 2024). Should CBDCs achieve widespread adoption, transactions might occur directly on institutionally controlled blockchains, potentially enabling real-time accounting and reducing the need for oracle systems in financial reporting. However, this solution would not extend to non-financial (e.g., ESG) reporting, which inherently depends on real-world data inputs. Although studies such as those published by Chen et al. (2024) and W. Wu et al. (2022a, 2022b) provide established frameworks for real-world asset (RWA) traceability, substantial technical hurdles remain. Most notably, the establishment of a reliable and tamper-proof connection between physical assets and their digital representations remains unresolved, limiting the robustness of ESG reporting infrastructures (Tanveer et al., 2025).

Overall, while the reviewed oracle architectures offer technically viable pathways for integrating blockchain technology into accounting and ESG reporting, their theoretical underpinnings reveal persistent trade-offs that require further scholarly attention and empirical validation.

5.3. Implications for Developers, Accounting Professionals, and Standard Setters

The findings of this review highlight critical considerations for accounting and auditing professionals, as well as regulatory bodies, in the context of blockchain’s integration. First, accountants and auditors must recognize that the reliability of blockchain-based data fundamentally depends on oracle mechanisms. Consequently, it is essential to develop audit procedures that explicitly assess oracles’ reliability, data’s provenance, and the associated input-level controls. This includes verifying the identity and accountability of data providers and evaluating the robustness of oracle infrastructures.

For technology implementers and firms, this research underscores the importance of clearly disclosing oracle designs and associated governance structures. The choice of an oracle system should be guided by feasibility, scalability, and the specific context of financial or ESG reporting.

Regulators and standard setters are advised to update reporting and auditing standards by incorporating explicit guidance on oracle usage and disclosure requirements. Policies should ensure transparency concerning the oracle mechanisms used, data’s provenance, and the accountability structures for real-world data providers. Finally, ongoing professional training and education programs must address misconceptions regarding the capabilities of blockchains, particularly emphasizing that immutability and decentralization do not inherently guarantee data’s reliability or eliminate the need for trusted intermediaries.

Small and medium-sized enterprises (SMEs), particularly those navigating new ESG reporting requirements, should exercise caution when evaluating blockchain-based solutions. Given the resource-intensive nature of advanced oracle implementations and the current lack of standardized best practices, SMEs are advised to prioritize transparency, verifiability, and accountability over technological complexity. Where blockchain is used, permissioned systems supported by existing attestation services may offer a more practical and cost-effective path. Importantly, SMEs should seek clear guidance from technology providers on how external data are sourced and validated and ensure that any integration aligns with their internal control capacities and reporting obligations.

6. Conclusions

This study extended the work of Sargent (2022) by offering a more detailed analysis of conceptual and technical limitations in the existing academic literature on the integration of blockchain in accounting. Building on (Caldarelli, 2020a), this study also systematically mapped and assessed the presence of oracle problem awareness across academic contributions. The obtained findings provided answers to this article’s research questions, indicating the following:

(1)

While oracles were mentioned in 33% of the retrieved sample, they are rarely explained in technical depth or integrated meaningfully into proposed blockchain architectures for accounting use cases.

(2)

References to oracles and their implementation appear predominantly in empirical studies that focus on specific blockchain platforms.

(3)

Roughly 25% of the sample exhibited overexpectations about blockchain capabilities. However, only 6% of the papers included any discussion of oracles that had overexpectations, suggesting that attention to the oracle layer significantly reduces the likelihood of unrealistic claims.

(4)

In accounting applications, the most common oracle schemes involve either a trusted authority that is responsible for data verification or bilateral validation by transacting parties. More advanced proposals include distributed validation by multiple nodes or cryptographic attestation services. For non-financial reporting, several studies have proposed the use of IoT devices or coordinated IoT systems as data providers.

(5)

The few studies offering more advanced oracle designs are largely found in ESG reporting contexts. However, practical implementations remain underdeveloped.

This research further revealed that the literature has given scant consideration to the roles of oracles in asset pricing and real-time data input, which is crucial given the increasing presence of cryptoassets in financial statements. In particular, the accounting and auditing professions appear unprepared to deal with these data sources. While many proposals assume that all relevant transactions will be natively recorded on-chain, this scenario remains implausible for cryptocurrencies in the short term. However, the emergence of central bank digital currencies (CBDCs) may offer a native infrastructure that supports real-time smart auditing, potentially displacing the need for custom blockchain implementations in traditional accounting.

An important limitation of this study is its exclusive focus on the academic literature, excluding white papers, working papers, and practitioner-oriented documentation. While academic papers often reference initiatives by major auditing firms, they rarely specify the oracle designs or implementation choices adopted (Abdennadher et al., 2022; Garanina et al., 2022; Alkhwaldi et al., 2024). Additionally, manual coding procedures might introduce interpretive subjectivity, despite rigorous criteria and categorization processes. Language bias is another consideration: as the review included only articles written in English, significant contributions published in other languages may have been overlooked. Finally, the breadth and heterogeneity of the blockchain literature pose definitional ambiguities and challenges in terms of standardizing terminology and analytical categories.

Given the highlighted findings, some research directions are proposed in order to address the gaps in the existing literature.

First, more empirical testing is needed. For example, how effective are existing oracle mechanisms in ensuring data’s reliability for blockchain-based accounting and ESG reporting?

While the literature offers some proposals for oracle designs, only empirical testing can yield reliable insights into their ultimate utility. Leveraging third-party oracles for research purposes is also a viable option, as many protocols are open-source and provide open-access manuals. Additionally, protocol foundations often finance the use of test nets, which can be leveraged for research purposes. Grants are frequently awarded for promising integration proposals.

Second, comparative analyses of oracle architectures for reporting purposes should be conducted, in order to inquire into the potential and drawbacks of different designs and implementations. The reviewed literature acknowledges alternative hypotheses, the potential of which has been speculated on; however, a more thorough analysis is required.

Third, as previously discussed, many accounting firms are launching pilot projects that integrate blockchain technology. However, what types of oracle mechanisms do they leverage, and what impacts do they have on the reliability of accounting data? Case studies can then be conducted on the basis of these pilot projects, and a detailed overview of the selected oracle can be provided. Qualitative data can also be used to assess the awareness of accountants and auditors regarding the potential of blockchain–oracle integration and the related implications for earnings management.

Finally, although numerous researchers have discussed the ability of CBDCs to enable real-time accounting, more dedicated research is needed to examine how native on-chain accounting via CBDCs could reshape reporting ecosystems and reduce reliance on oracle systems.