Isogeny-Based Quantum-Resistant Group Key Agreement (Q20c)
This presentation will show the first quantum-resistant $n$-party key agreement scheme based on supersingular elliptic curve isogenies. The presenter will show that the scheme is secure against quantum adversaries, by providing a security reduction to an intractable isogeny problem. The speaker will describe the communication and computational steps required for $n$ parties to establish a common shared secret key. The scheme is the first non-generic quantum resistant group key agreement protocol, and is more efficient than generic protocols, with near-optimal communication overhead. In addition, the scheme is contributory, which in some settings is a desirable security property: each party applies a function of their own private key to every further transmission.