BLISS (short for Bimodal Lattice Signature Scheme) is a digital signature scheme proposed by Léo Ducas, Alain Durmus, Tancrède Lepoint and Vadim Lyubashevsky in their 2013 paper "Lattice Signature and Bimodal Gaussians".
In cryptography, digital signature ensures that a message is authentically from a specific person who has the private key to create such signature, and such signature can be verified using the corresponding public key. Current signature schemes relies on one of integer factorization, discrete logarithm, and elliptic curve discrete logarithm problem, which can be effectively attacked by a quantum computer. BLISS on the other hand, is a post-quantum algorithm, and is meant to resist quantum computer attacks.
Compared to other post-quantum schemes, BLISS claims to offer better computational efficiency, smaller signature size, and higher security. A presentation given at NIST has therefore anticipated that BLISS be further refined and become a potential candidate for standardization.