HCASH Chief Scientist, Dr Joseph Liu and his and his colleagues’ paper “Lattice RingCT V2.0 with Multiple Input and Multiple Output Wallets” is to be published by the Australasian Conference on Information Security and Privacy (ACISP) this July.

This paper is written by Wilson Alberto Torres, Veronika Kuchta, Ron Steinfeld, Amin Sakzad, Joseph K. Liu, and Jacob Cheng, which presents the Lattice-based Ring Confidential Transactions “Lattice RingCT v2.0” protocol. Unlike the previous Lattice RingCT v1.0 (LRCT v1.0) protocol, which was published last year by the International Association for Cryptologic Research, the new protocol supports Multiple-Input and Multiple-Output (MIMO) wallets in transactions, and is a fully functional protocol construction for cryptocurrency applications such as HCASH.

Since the MIMO cryptocurrency setting introduces new balance security requirements (and in particular, security against out-of-range amount attacks), this paper gives a refined balance security model to capture such attacks, as well as a refined anonymity model to capture amount privacy attacks. LRCT v2.0 extends a previously proposed ring signature scheme in the LRCT v1.0 protocol, to support the MIMO requirements while preserving the post-quantum security guarantees, and uses a lattice-based zero-knowledge range proof to achieve security against out-of-range attacks.

The HyperCash development team has completed and released code for the implementation of Post-Quantum Linkable Ring Signatures in HC this February. This algorithm is based on a previous publication “Post-Quantum One-Time Linkable Ring Signature and Application to Ring Confidential Transactions in Blockchain” (Lattice RingCT v1.0), which was also written by Dr. Joseph Liu and his colleagues. Now with the Lattice RingCT v2.0 paper being published, the HCASH development team will improve their RingCT v2.0 Code in the future, to provide users with more Ring Signature, Blockchain Security, and Privacy Protection technologies.

Please refer to https://medium.com/@media_30378/ring-signatures-blockchain-security-and-privacy-protection-technologies-50c7b90db30e for more information about Ring Signatures, Blockchain Security, and Privacy Protection.

The first version, Post-Quantum One-Time Linkable Ring Signature and Application to Ring Confidential Transactions in Blockchain (Lattice RingCT v1.0) can be found here: https://eprint.iacr.org/2018/379.pdf