Cryptographic Corollaries of the Classification of Finite Simple Groups
Talk, NIST Crypto Reading Club, NIST Campus, USA
The Semidirect Discrete Logarithm Problem (SDLP) is a potentially appealing generalisation of the standard Discrete Logarithm Problem (DLP) arising from a more involved algebraic structure. It was hoped that there would be a gap between the quantum complexity of SDLP and that of DLP, allowing for development of post-quantum schemes based on SDLP.Unfortunately, in the case of SDLP with respect to finite groups, this turns out not to be the case. In this talk we present two powerful tools allowing us to reach this conclusion: the first is a method of decomposition of a generic instance of SDLP into several instances of SDLP in a finite simple group; the second is a survey of SDLP in each finite simple group, aided by the celebrated classification theorem.