The quest of privacy in public key infrastructure. (13th December 2021)

• Record Type: Journal Article
• Authors: Benarous, Leila; Kadri, Benamar
• Is Part Of: International journal of blockchains and cryptocurrencies. Volume 2:Number 3(2021)
• Page Start: 244
• Page End: 262
• Publication Date: 2021-12-13
• Subjects: public key infrastructure -- PKI -- blockchain -- privacy -- elliptic curve cryptography -- ECC -- pseudonyms -- certificates -- revocation; Blockchains (Databases) -- Periodicals; Cryptocurrencies -- Periodicals; Electronic funds transfers -- Periodicals; 332.404
• Languages: English
• ISSNs: 2516-6425

Abstract

The public key infrastructure (PKI) is the backbone of internet security. It ensures the authenticity, integrity, and non-repudiation. The certified public keys are life-timed. They may be revoked upon personal change, private key exposure or misbehaviour occurrence. Their use is secure and traceable. Yet, this traceability trait and the identity-based certificate usage may violate the user's privacy. Therefore, there needs to be a balance between the accountability and authenticity requirements on the one hand and the privacy demand on the other hand. In this paper, we design a blockchain-based privacy-aware public key infrastructure system, which guarantees the same security properties besides ensuring the privacy. The users have two types of elliptic curve cryptography (ECC) keys, identity-based long-term certified keys and on-the-fly temporal anonymous keys denoted as pseudonyms. These pseudonyms are stored and published on the blockchain. The proposed PKI achieves a similar security level as that of the conventional PKI while ensuring the privacy.