Paper 2019/654

Concise Linkable Ring Signatures and Forgery Against Adversarial Keys

Brandon Goodell and Sarang Noether and RandomRun

Abstract

We demonstrate that a version of non-slanderability is a natural definition of unforgeability for linkable ring signatures. We present a linkable ring signature construction with concise signatures and multi-dimensional keys that is linkably anonymous if a variation of the decisional Diffie-Hellman problem with random oracles is hard, linkable if key aggregation is a one-way function, and non-slanderable if a one-more variation of the discrete logarithm problem is hard. We remark on some applications in signer-ambiguous confidential transaction models without trusted setup.

Note: Updated security model, with extensive revisions.