The code for the post-quantum secure linkable ring signature scheme, proposed to be implemented in HC has been released.
The original paper, written by Wilson Alberto Torres, Ron Steinfeld, Amin Sakzad, Joseph K. Liu, Veronika Kuchta, Nandita Bhattacharjee, Man Ho Au and Jacob Cheng, proposed a new method of verifying two or more signatures generated by the same signatory, whilst preserving their anonymity unconditionally. This was constructed using a lattice-based one-time linkable ring signature scheme, or L2RS. In addition to user anonymity, transaction amounts are hidden, and the system is protected against attacks from quantum computers.
The Chainchip team has been working to develop and test working code to be implemented in HC. Their work is linked below.
https://github.com/chainchip/Lattice-RingCT-v2.0