A Lower Bound on the Length of Signatures Based on Group Actions and Generic Isogenies

ePrint Report: A Lower Bound on the Length of Signatures Based on Group Actions and Generic Isogenies

Dan Boneh, Jiaxin Guan, Mark Zhandry

We give the first black box lower bound for signature protocols that can be described as group actions, which include many based on isogenies. We show that, for a large class of signature schemes making black box use of a (potentially non-abelian) group action, the signature length must be $\Omega(\lambda^2/\log\lambda)$. Our class of signatures generalizes all known …

actions black box box class dan eprint report large length making mark non protocols report signature signatures