Edwards-Curve Digital Security Algorithm (EdDSA) for DNSSEC
Extracted elements (15)
Ed448 is provided for applications with relaxed performance requirements and where there is a desire to hedge against analytical attacks on elliptic curves, offering higher security margin than Ed25519.
The use of Ed25519 and Ed448 with Transaction Security has not been standardized; the Trans. Sec. column in the IANA registry is marked '*' indicating no determination.
Algorithm number 15 is assigned to Ed25519 for use in DS, DNSKEY, and RRSIG resource records; algorithm number 16 is assigned to Ed448.
An Ed25519 public key consists of a 32-octet value, encoded into the Public Key field of a DNSKEY resource record as a simple bit string.
An Ed25519 signature consists of a 64-octet value, encoded into the Signature field of an RRSIG resource record as a simple bit string.
An Ed448 public key consists of a 57-octet value, encoded into the Public Key field of a DNSKEY resource record as a simple bit string.
An Ed448 signature consists of a 114-octet value, encoded into the Signature field of an RRSIG resource record as a simple bit string.
This document adds entries for Ed25519 (algorithm 15, mnemonic ED25519) and Ed448 (algorithm 16, mnemonic ED448) to the IANA 'Domain Name System Security (DNSSEC) Algorithm Numbers' registry, both supporting zone signing.
A private key used for a DNSSEC zone MUST NOT be used for any other purpose than for that zone, to prevent cross-protocol or cross-application attacks.
Ed25519 is intended to operate at around the 128-bit security level and Ed448 at around the 224-bit security level; a sufficiently large quantum computer would be able to break both.
The security considerations of RFC 8032 (EdDSA) and RFC 7748 (elliptic curves for security) are inherited in the usage of Ed25519 and Ed448 in DNSSEC.
The Ed25519 public key field in DNSKEY RR is a 32-octet simple bit string encoding the public key as defined in RFC 8032 Section 5.1.5.
The Ed25519 signature field in RRSIG RR is a 64-octet simple bit string; algorithm and verification follow RFC 8032 Sections 5.1.6 and 5.1.7.
The Ed448 public key field in DNSKEY RR is a 57-octet simple bit string encoding the public key as defined in RFC 8032 Section 5.2.5.
The Ed448 signature field in RRSIG RR is a 114-octet simple bit string; algorithm and verification follow RFC 8032 Sections 5.2.6 and 5.2.7.