Optimal Key Consensus in Presence of Noise

Understand

In this work, we abstract some key ingredients in previous LWE- and RLWE-based key exchange protocols, by introducing and formalizing the building tool, referred to as key consensus (KC) and its asymmetric variant AKC.

• KC and AKC allow two communicating parties to reach consensus from close values obtained by some secure information exchange.
• We then discover upper bounds on parameters for any KC and AKC.
• KC and AKC are fundamental to lattice based cryptography, in the sense that a list of cryptographic primitives based on LWR, LWE and RLWE (including key exchange, public-key encryption, and more) can be modularly constructed from them.