The cryptographic algorithm and key size requirements included when DomainKeys Identified Mail (DKIM) was designed a decade ago are functionally obsolete and in need of immediate revision. This document updates DKIM requirements to those minimally suitable for operation with currently specified algorithms.
This document adds a new signing algorithm, Ed25519-SHA256, to "DomainKeys Identified Mail (DKIM) Signatures" (RFC 6376). DKIM verifiers are required to implement this algorithm.