Special Issue: Symmetric and Asymmetric Encryption in Blockchain

The technology that is most likely to change the corporate world in the next ten years is not social networks, Big Data, cloud computing, robots, not even artificial intelligence, but blockchain. The main characteristics of blockchain technology are decentralization, high credibility, versatility, transparency, autonomy, non-changeable information, anonymity, traceability, irreversibility, intelligence, reward mechanism, and other characteristics. Blockchain technology is essentially a decentralized and open and transparent distributed database maintained by the collective. It has the characteristics of reliability and high confidentiality and has a good prospect of effectively solving the trust problem between the parties to the transaction. Credit is the basis for the production and maintenance of social relations between people and organizations. At present, people mainly use regulations, systems, laws, contracts, etc. to restrict credit problems. These methods cannot solve the credit problem due to many human subjective factors. Blockchain can achieve collaboration and trust between multiple entities through smart contracts, thereby expanding the scope and depth of mutual cooperation between roles. Symmetry is one of the most important notions in natural science. The purpose of this Special Issue is to provide a forum for researchers and practitioners to exchange ideas and progress in related areas. This Special Issue has collected 10 papers, which are detailed as follows:

(1)

IoT and Blockchain for Supply Chain Application

Three papers on Supply Chain Applications are as follows: (1) “Towards Convergence of IoT and Blockchain for Secure Supply Chain Transaction” by Hasan et al. [1]; (2) “An Anti-Counterfeit and Traceable Management System for Brand Clothing with Hyperledger Fabric Framework,” by Chen et al. [2]; (3) “Data Security and Preservation Mechanisms for Industrial Control Network Using IOTA” by Lin et al. [3].

Among the accepted papers, Hasan et al. [1] proposed a unified solution with distributed ledger technology, i.e., Hyperledger fabric, IoT, and elliptic curve cryptography, to protect the transaction data from privacy and security breaches. ECC ensured the lightweight cryptographic operations and authentication of IoT devices. Authenticated IoT scanner guarantees an error-free supply chain transaction enabling the trusted immutable ledger among all participants. Rigorous implementation of the proposed system on the Hyperledger fabric network confirmed that the system works smoothly in a multi-party setup. The result and security analysis proves that the proposed system is robust and secure for real-life applications.

In [2], Chen et al. proposed a Hyperledger-Fabric-based anti-counterfeit management system for traceable designer apparel. We contributed to the anti-counterfeiting of brand-name clothing. In this paper, the authors proposed a system framework that combined blockchain and supply chain, and analyzed and explained each process in the supply chain in detail. The production and sales processes are recorded in the blockchain network so that customers could easily trace the anti-counterfeiting of the purchased branded clothing through the blockchain network. The third-party arbitration mechanism can also be used to check the illegal part of the supply chain easily. It provides adequate protection for the whole production parties and customers of brand clothing.

Moreover, Lin et al. proposed an IoT architecture based on the IOTA Tangle network to solve the centralization problem of IoT storage in the cloud and uses the method of MAM (Masked Authenticated Message) to trace the information of WSNs, while achieving data security and data preservation. In the edge devices of WSNs, because of the insufficient memory and computing performance of many devices, it is impossible to perform proof of work calculations. Therefore, this paper uses the logical key hierarchy-based method to manage the sensors and applies symmetric and asymmetric encryption in the blockchain. The identity verification of the device can be effectively achieved, and the operating cost can be effectively reduced.

(2)

Cryptography and Blockchain Application

Four papers on Cryptography and Blockchain Application are as follows: (1) “A Digital Media Subscription Management System Combined with Blockchain and Proxy Re-Encryption Mechanisms” by Huang et al. [4]; (2) “An artwork rental system based on blockchain technology” by Huang et al. [5]; (3) “A Collective Anomaly Detection Technique to Detect Crypto Wallet Frauds on Bitcoin Network” by Mohammad et al. [6]; (4) “An Approach for Blockchain Pool Mining Employing the Consensus Protocol Robust against Block Withholding and Selfish Mining Attacks” by Miodrag et al. [7].

Huang et al. [4] proposed a digital media subscription mechanism based on the Hyperledger blockchain architecture combined with proxy re-encryption. The authors used symmetric and asymmetric cryptography, smart contracts, and algorithms to design the protocol. When the licensee violates the agreement with the creator, the creator can revoke the access rights to the digital media of the licensee at any time, to realize more secure and convenient digital media transmission. The proposed scheme meets various security requirements of blockchain architecture, and the authors have also applied the BAN logic proof model to evaluate the correctness of the proposed scheme. This study also proposes an arbitration mechanism when the dispute occurs, and performed well in terms of communication and computational costs.

In [5], the proposed scheme applied the characteristics of blockchain technology to Art Bank’s art rental system, and it will gain the following advantages: Using Hyperledger technology, the various art banks are merged into an alliance, and information among alliance members can be shared, which is convenient for tenants to comprehensively query a single item. Using blockchain technology, in an environment where there is no central authority, under the premise of preventing the tampering of artwork-related information, ensures that the detailed information of the art-work information is shared. Compile traditional leasing agreements into smart contract leasing contracts to automatically run and manipulate data. The proposed protocol satisfies the following security requirements: identities’ mutual authentication, non-repudiation between every two parties, and also other major security requirements based on blockchain. When a dispute arises, our proposed scheme also has an arbitration mechanism to clarify responsibilities.

In addition, Mohammad et al. [6] used the blockchain technology of symmetry and asymmetry in computer and engineering science to present a new method for detecting anomalies in Bitcoin with more appropriate efficiency. In this study, a collective anomaly approach was used. Instead of detecting the anomaly of individual addresses and wallets, the anomaly of users was examined. In addition to using the collective anomaly detection method, the trimmed_Kmeans algorithm was used for clustering. The results of this study show the anomalies are more visible among users who had multiple wallets.

In [7], the authors proposed an approach for pool mining in public blockchain systems based on the employment of a recently reported consensus protocol with the puzzle based on symmetric encryption that provides an energy–space trade-off and reduces energy consumption. The proposed architecture employs a pseudo-symmetric allocation of the resources for the blockchain consensus protocol and protects certain malicious actions of the pool members, as well as a miner’s opportunity for selecting the resources required for participation in the consensus protocol. Given that the considered consensus protocol employs two resources, the proposed architecture uses this two-dimensional nature to provide resistance against block withholding and selfish mining attacks, as well as a reduction in energy spending as a trade-off with the employment of certain memory resources.

(3)

Cryptography and Fuzy Application

Three papers on Cryptography and Blockchain Applications are as follows: (1) “Asymmetric Orientation Combination for Reversible and Authenticable Data Hiding of Dual Stego-images” by Lin et al. [8]; (2) “Encryption Techniques for Smart Systems Data Security Offloaded to the Cloud” by Muhammad et al. [9]; (3) Benefits Evaluation Method of an Integrated Energy System Based on a Fuzzy Comprehensive Evaluation Method” by Cao et al. [10].

Lin et al. [8] first proposed a full search algorithm to find the optimal set of reversible orientation combinations. Based on the algorithm, the modification range of pixel values can be dynamically enlarged, and thus the embedding capacity becomes adjustable. In addition, an authentication algorithm is provided to detect tampered shadows based on a faithful one. Experimental results confirm that the proposed scheme can produce dual stego-images with good visual quality. Furthermore, the method provides an adjustable payload. A lot more secret data can be embedded than with state-of-the-art methods, with satisfactory image quality. Two steganalysis tools are applied to demonstrate the security level of the proposed scheme.

The main objective of the cloud computing system [9] is to provide on-demand storage and computing resources to the users on the pay-per-use policy. It allows small businesses to use top-notch infrastructure at low expense. However, due to the cloud resource sharing property, data privacy and security are significant concerns and barriers for smart systems to constantly transfer generated data to the cloud computing resources, which a third-party provider manages. Many encryption techniques have been proposed to cope with data security issues. In this paper, different existing data protection and encryption techniques based on common parameters have been critically analyzed and their workflows are graphically presented. This survey aims to collect existing data encryption techniques widely presented in the literature for smart system data security offloaded to cloud computing systems under a single umbrella.

Finally, Cao et al. attempted to design an evaluation method that considers the renewable energy and energy system model for evaluating the benefit of an IES. Firstly, this paper constructed an evaluation index system including four dimensions of technology, economy, environment, and society, based on the physical architecture of IES and its benefit influencing factors. It focuses on multiple energy sources or systems, and satisfies the overall evaluation of IES, resulting in accurate benefit evaluation results. Secondly, the subjective weight is determined by combining the triangular fuzzy number (TFN) and the analytic hierarchy process (AHP). The objective weight is determined by the entropy method. The combined weight is obtained by combining the subjective and objective weights, which solves the problem of the weight calculation error caused by the mutual influence between the indexes. Finally, the fuzzy comprehensive evaluation method is used to conduct the benefit evaluation of the IES, which solves the problem that the qualitative index cannot be calculated. This paper takes an IES project in a city in northern China as a case study. Through sensitivity analysis and comparative analysis, the reliability and feasibility of the evaluation results and proposed method are verified. The analysis results show that the model evaluation results are intuitive and consistent with reality, and the data information utilization rate is high.