Privacy-Preserving Authentication — Cryptography, Key Management, Post-Quantum, Sovereign AI, and Post-Cloud Architecture (Mf+So)

Abstract

This paper presents a comprehensive analysis of privacy-preserving authentication mechanisms within the MF+SO sovereign identity vault, focusing on the protocol's implementation of zero-knowledge identity proofs, anonymous credentials, blind signatures, and data minimization techniques. Traditional authentication protocols require the user to disclose their identity to each service provider, creating a centralized record of the user's activities across services. MF+SO's privacy architecture inverts this model: users authenticate to services without revealing their MF+SO identifier, using cryptographic techniques that provide the verifier with assurance of the user's authorization status while revealing minimal information about the user's identity. We examine three canonical privacy-preserving authentication mechanisms implemented in MF+SO: (1) zero-knowledge identity proofs using the Groth16 zk-SNARK construction, enabling users to prove possession of valid credentials without revealing which credentials they hold; (2) anonymous credentials based on the Camenisch-Lysyanskaya (CL) signature scheme, providing multi-show unlinkability where the same credential can be presented multiple times without the presentations being correlatable; and (3) blind signature-based tokens for email cloaking, where the MF+SO service issues a blind signature on a user's email address for use with third-party services without learning the email address. The paper provides a formal security analysis of the unlinkability guarantees of each mechanism, proving that under the decisional Diffie-Hellman (DDH) assumption, CL-based anonymous credential presentations are computationally unlinkable. We present benchmark data for each mechanism on mobile platforms: CL credential issuance (120 ms), CL credential presentation (85 ms), blind RSA signature issuance (45 ms), and zk-SNARK-based verification (2.3 ms). The implementation details include the MF+SO privacy layer architecture, the credential ... Part of The Anticloud research corpus by Lois-Kleinner Alpasan (ORCID: 0009-0009-2233-6107). This work explores cryptography, key management in the context of sovereign AI infrastructure, post-cloud computing architectures, and transparent, blackbox-free systems.