Privacy-preserving age and identity verification via anonymous credentials
6 hours ago
- #authentication
- #privacy
- #cryptography
- Anonymous authentication is becoming increasingly important due to privacy concerns driven by bad legislation and AI proliferation.
- Traditional authentication methods often require revealing personal information, leading to privacy risks.
- Anonymous credentials, proposed by David Chaum, allow authentication without revealing identity, breaking the link between credential issuance and usage.
- Simple anonymous credentials can be thought of as digital wristbands, where the issuer knows your identity but the service only sees the credential.
- A major challenge with anonymous credentials is preventing credential duplication, which can lead to abuse.
- Solutions to prevent credential duplication include single-use credentials, revocable credentials, and hardware-tied credentials.
- Zero-knowledge (ZK) proofs can enhance anonymous credentials by allowing users to prove specific attributes without revealing unnecessary information.
- ZK proofs also enable credential reusability without linking multiple uses to the same user.
- Revocation of anonymous credentials is possible through techniques like banlists, where banned users are prevented from using their credentials.
- Real-world implementations of anonymous credentials include PrivacyPass and Google's new proposal for Android phones.