Hardening DNSSEC against collision weaknesses in SHA-1 and other cryptographic hash algorithms

Hardening DNSSEC against collision weaknesses in SHA-1 and other cryptographic hash algorithms University of Cambridge DNSSEC deployments have often used the SHA-1 cryptographic hash algorithm to provide authentication of DNS data. This document explains why SHA-1 is no longer secure for this purpose, and deprecates its use in DNSSEC signatures. This document updates RFC 8624.