An Improved Threshold Homomorphic Cryptosystem Based on Class Groups

ePrint Report: An Improved Threshold Homomorphic Cryptosystem Based on Class Groups

Lennart Braun, Guilhem Castagnos, Ivan Damgård, Fabien Laguillaumie, Kelsey Melissaris, Claudio Orlandi, Ida Tucker

We present distributed key generation and decryption protocols for an additively homomorphic cryptosystem based on class groups, improving on a similar system proposed by Braun, Damgård, and Orlandi at CRYPTO '23. Our key generation is similarly constant round but achieves lower communication complexity than the previous work. This improvement is in part the result of …

class decryption distributed eprint report ida key protocols report system threshold