Post-quantum one-time linkable ring signature and application to ring confidential transactions in blockchain (Lattice RingCT v1.0)

Abstract

In this paper, we construct a Lattice-based one-time Linkable Ring Signature (L2RS) scheme, which enables the public to verify if two or more signatures were generated by same signatory, whilst still preserving the anonymity of the signatory. The L2RS provides unconditional anonymity and security guarantees under the Ring Short Integer Solution (Ring-SIS) lattice hardness assumption. The proposed L2RS scheme is extended to be applied in a protocol that we called Lattice Ring Confidential transaction (Lattice RingCT) v1.0, which forms the foundation of the privacy-preserving protocol in any post-quantum secure cryptocurrency such as Hcash.