Enum CoseAlgorithmIdentifier

Namespace

Yubico.YubiKey.Fido2.Cose

Assembly

Yubico.YubiKey.dll

Represents a COSE algorithm identifier. This enumeration is based on the IANA COSE Algorithms registry.

https://www.iana.org/assignments/cose/cose.xhtml#algorithms

public enum CoseAlgorithmIdentifier

Fields

ECDHwHKDF256 = -25

ECDH with key derivation function HKDF using SHA-256.

ES256 = -7

ECDSA with SHA-256, usually using the NIST P-256 curve.

COSE generally constrains the hash function, while WebAuthn/FIDO2 constrains this identifier to NIST P-256. See https://www.w3.org/TR/2026/CR-webauthn-3-20260526/#sctn-alg-identifier.

ES384 = -35

ECDSA with SHA-384, usually using the NIST P-384 curve.

COSE generally constrains the hash function, while WebAuthn/FIDO2 constrains this identifier to NIST P-384. See https://www.w3.org/TR/2026/CR-webauthn-3-20260526/#sctn-alg-identifier.

ES512 = -36

ECDSA with SHA-512, usually using the NIST P-521 curve.

COSE generally constrains the hash function, while WebAuthn/FIDO2 constrains this identifier to NIST P-521. See https://www.w3.org/TR/2026/CR-webauthn-3-20260526/#sctn-alg-identifier.

ESP256 = -9

ECDSA using the NIST P-256 curve and SHA-256. See Section 2.1 of RFC 9864: https://www.rfc-editor.org/rfc/rfc9864.html#name-elliptic-curve-digital-sign

EdDSA = -8

ECDSA using the Ed25519 curve and "Pure" EdDSA which uses no digest algorithm.

None = 0

No algorithm specified.

RS256 = -257

RSASSA-PKCS1-v1_5 with SHA-256 Currently, not supported by any YubiKey