XORSFRO: A Resource-Efficient XOR Self-Feedback Ring Oscillator-Based TRNG Architecture for Securing Distributed Photovoltaic Systems

Guo, Wei; Xia, Rui; Wang, Jingcheng; Ding, Bosong; Xiong, Chao; Zhao, Yuning; Li, Jinping

doi:10.3390/electronics15010071

Open AccessArticle

XORSFRO: A Resource-Efficient XOR Self-Feedback Ring Oscillator-Based TRNG Architecture for Securing Distributed Photovoltaic Systems

by

Wei Guo

¹,

Rui Xia

²,

Jingcheng Wang

¹,

Bosong Ding

²,

Chao Xiong

²,

Yuning Zhao

^3,* and

Jinping Li

^4,*

¹

Xi’an Thermal Power Research Institute Co., Ltd., Xi’an 710054, China

²

Anhui Wind Power Branch, Huaneng Power International Co., Ltd., Hefei 230071, China

³

School of Computer Science and Technology, Xidian University, Xi’an 710071, China

⁴

School of Computer Science and Technology, Xi’an University of Posts & Telecommunications, Xi’an 710121, China

^*

Authors to whom correspondence should be addressed.

Electronics 2026, 15(1), 71; https://doi.org/10.3390/electronics15010071

Submission received: 5 November 2025 / Revised: 9 December 2025 / Accepted: 10 December 2025 / Published: 23 December 2025

(This article belongs to the Special Issue New Trends in Cybersecurity and Hardware Design for IoT)

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Abstract

The performance of true random number generators (TRNGs) fundamentally depends on the quality of their entropy sources (ESs). However, many FPGA-friendly designs still rely on a single mechanism and struggle to achieve both high throughput and low resource cost. To address this challenge, we propose the exclusive OR (XOR) Self-Feedback Ring Oscillator (XORSFRO), an XORNOT-style TRNG that integrates two cross-connected XOR gates with a short inverter delay chain and clocked sampling. A unified timing model is developed to describe how arrival-time skew and gate inertial delay lead to cancellation, narrow-pulse generation, and inversion events, thereby enabling effective entropy extraction. Experimental results on Xilinx Spartan-6 and Artix-7 FPGAs demonstrate that XORSFRO maintains stable operation across standard process–voltage–temperature (PVT) variations, while achieving higher throughput and lower hardware overhead compared with recent FPGA-based TRNGs. The generated bitstreams pass both the NIST SP 800-22 and NIST SP 800-90B test suites without post-processing.

Keywords: TRNG; FPGA; XORSFRO; IoT; distributed PV security

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MDPI and ACS Style

Guo, W.; Xia, R.; Wang, J.; Ding, B.; Xiong, C.; Zhao, Y.; Li, J. XORSFRO: A Resource-Efficient XOR Self-Feedback Ring Oscillator-Based TRNG Architecture for Securing Distributed Photovoltaic Systems. Electronics 2026, 15, 71. https://doi.org/10.3390/electronics15010071

AMA Style

Guo W, Xia R, Wang J, Ding B, Xiong C, Zhao Y, Li J. XORSFRO: A Resource-Efficient XOR Self-Feedback Ring Oscillator-Based TRNG Architecture for Securing Distributed Photovoltaic Systems. Electronics. 2026; 15(1):71. https://doi.org/10.3390/electronics15010071

Chicago/Turabian Style

Guo, Wei, Rui Xia, Jingcheng Wang, Bosong Ding, Chao Xiong, Yuning Zhao, and Jinping Li. 2026. "XORSFRO: A Resource-Efficient XOR Self-Feedback Ring Oscillator-Based TRNG Architecture for Securing Distributed Photovoltaic Systems" Electronics 15, no. 1: 71. https://doi.org/10.3390/electronics15010071

APA Style

Guo, W., Xia, R., Wang, J., Ding, B., Xiong, C., Zhao, Y., & Li, J. (2026). XORSFRO: A Resource-Efficient XOR Self-Feedback Ring Oscillator-Based TRNG Architecture for Securing Distributed Photovoltaic Systems. Electronics, 15(1), 71. https://doi.org/10.3390/electronics15010071

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XORSFRO: A Resource-Efficient XOR Self-Feedback Ring Oscillator-Based TRNG Architecture for Securing Distributed Photovoltaic Systems

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