Improved Efficiency of a Linearly Homomorphic Cryptosystem
Parthasarathi Das, Michael J. Jacobson, Renate Scheidler · Lecture notes in computer science · 2019
We present an extended version of the Castagnos and Laguillaumie linearly homomorphic cryptosystem [ 5 ] in which the non-maximal imaginary quadratic order is allowed to have conductor equal to a product of prime powers as opposed to a single prime. Numerical results obtained with an optimized C implementation demonstrate that this variation improves performance when large messages and exponents are used. When compared to the cryptosystems of Paillier [ 11 ] and Bresson et al. [ 3 ] at the same security levels, the basic version of Castagnos and Laguillaumie is the fastest at high security levels for small messages.