CRC Seminar Series - Peter Schwabe

Title:

Cryptographic protocols for the post-quantum era: PQ-WireGuard and KEMTLS

Abstract:

Over the last decade, and in particular after NIST's call for post-quantum crypto proposals in 2016, the field of applied post-quantum cryptography has advanced significantly. Most research in this area has been dedicated to designing, optimizing, analyzing, and securely implementing post-quantum primitives -- most notably key-encapsulation mechanisms (KEMs)and signatures. In this talk we will look beyond these primitives and consider two examples of what it means to migrate cryptographic protocols to the post-quantum era. Specifically, we will look at a post-quantum version of the WireGuard VPN protocol and at KEMTLS, an alternative to the TLS handshake that derives authentication from long-term KEM keys instead of signatures. We will see that post-quantum protocol design goes beyond simply replacing currently used elliptic-curve primitives by post-quantum equivalents; either because such equivalents are not readily available, or because performance characteristics of post-quantum primitives are so different to their elliptic-curve counterparts that changes on protocol level yield more efficient constructions.