PoS Blockchain-Based Forward-Secure Public Key Encryption with Immutable Keys and Post-Compromise Security Guarantees

【Author】 Nuta, Seiya; Schuldt, Jacob C. N.; Nishide, Takashi

【Source】IEICE TRANSACTIONS ON FUNDAMENTALS OF ELECTRONICS COMMUNICATIONS AND COMPUTER SCIENCES

【影响因子】0.423

【Abstract】We present a forward-secure public-key encryption (PKE) scheme without key update, i.e. both public and private keys are immutable. In contrast, prior forward-secure PKE schemes achieve forward security by constantly updating the secret keys. Our scheme is based on witness encryption by Garg et al. (STOC 2013) and a proof-of-stake blockchain with the distinguishable forking property introduced by Goyal et al. (TCC 2017), and ensures a ciphertext cannot be decrypted more than once, thereby rendering a compromised secret key useless with respect to decryption of past ciphertext the legitimate user has already decrypted. In this work, we formalize the notion of blockchain-based forward-secure PKE, show the feasibility of constructing a forward-secure PKE scheme without key update, and discuss interesting properties of our scheme such as post-compromise security.

【Keywords】public-key encryption; forward security; blockchain

【发表时间】2023 MAR

【收录时间】2023-03-29

【文献类型】理论模型

【主题类别】

区块链技术-协同技术-密码学