SeND Hash Threat Analysis

This document analysis the use of hashes in SeND, possible threats and the impact of recent attacks on hash functions used by SeND. Current SeND specification [rfc3971] uses SHA-1 [sha-1] hash algorithm and PKIX certificates [rfc3280] and does not provide support for the hash algorithm agility. Based on previous analysis, this document suggests multiple hash support that should be included in the SeND update specification.