2020/02/23 by Onuki, Hiroshi
#FOS: Mathematics #Number Theory (math.NT)
paper · doi:10.48550/arxiv.2002.09894
We revisit theoretical background on OSIDH, that is an isogeny-based key-exchange protocol proposed by Colò and Kohel at NutMiC 2019. We give a proof of a fundamental theorem for OSIDH. The theorem was stated by Colò and Kohel without proof. Furthermore, we consider parameters of OSIDH, give a sufficient condition on the parameters that the protocol works, and estimate the size of the parameters for a certain security level.