CBOR Object Signing and Encryption (COSE) Created 2017-01-11 Last Updated 2021-05-28 Available Formats [IMG] XML [IMG] HTML [IMG] Plain text Registries included below * COSE Header Parameters * COSE Header Algorithm Parameters * COSE Algorithms * COSE Key Common Parameters * COSE Key Type Parameters * COSE Key Types * COSE Elliptic Curves COSE Header Parameters Expert(s) Francesca Palombini, Matt Miller, Justin Richer, Carsten Bormann Reference [RFC-ietf-cose-rfc8152bis-struct-15] Available Formats [IMG] CSV Range Registration Procedures Integer values in the range -1 to -65536 delegated to the COSE Header Algorithm Parameters registry Integer values between 1 and 255 Standards Action With Expert Review Integer values from 256 to 65535 Specification Required Integer values greater than 65535 Expert Review Strings of length 1 Standards Action With Expert Review Strings of length 2 Specification Required Strings of length greater than 2 Expert Review Name Label Value Type Value Registry Description Reference Reserved for Private Use less than [RFC-ietf-cose-rfc8152bis-struct-15] -65536 delegated to the COSE Header -65536 to Algorithm Parameters registry -1 Reserved 0 [RFC-ietf-cose-rfc8152bis-struct-15] alg 1 int / tstr COSE Algorithms Cryptographic [RFC-ietf-cose-rfc8152bis-struct-15] registry algorithm to use crit 2 [+ label] COSE Header Parameters Critical headers to [RFC-ietf-cose-rfc8152bis-struct-15] registry be understood [COAP Content-Formats] Content type of the content type 3 tstr / uint or [Media Types] payload [RFC-ietf-cose-rfc8152bis-struct-15] registry kid 4 bstr Key identifier [RFC-ietf-cose-rfc8152bis-struct-15] IV 5 bstr Full Initialization [RFC-ietf-cose-rfc8152bis-struct-15] Vector Partial IV 6 bstr Partial [RFC-ietf-cose-rfc8152bis-struct-15] Initialization Vector counter signature 7 COSE_Signature / [+ CBOR-encoded [RFC8152] COSE_Signature ] signature structure Unassigned 8 Counter signature CounterSignature0 9 bstr with implied signer [RFC8152] and headers Identifies the kid context 10 bstr context for the key [RFC8613, Section 5.1] identifier Unassigned 11-31 x5bag (TEMPORARY - registered An unordered bag of 2019-08-20, extension registered 32 COSE_X509 X.509 certificates [draft-ietf-cose-x509] 2020-07-28, expires 2021-08-20) x5chain (TEMPORARY - registered An ordered chain of 2019-08-20, extension registered 33 COSE_X509 X.509 certificates [draft-ietf-cose-x509] 2020-07-28, expires 2021-08-20) x5t (TEMPORARY - registered Hash of an X.509 2019-08-20, extension registered 34 COSE_CertHash certificate [draft-ietf-cose-x509] 2020-07-28, expires 2021-08-20) x5u (TEMPORARY - registered URI pointing to an 2019-08-20, extension registered 35 uri X.509 certificate [draft-ietf-cose-x509] 2020-07-28, expires 2021-08-20) Unassigned 36-255 CUPHNonce 256 bstr Challenge Nonce [FIDO Device Onboard Specification] CUPHOwnerPubKey 257 array Public Key [FIDO Device Onboard Specification] COSE Header Algorithm Parameters Registration Procedure(s) Expert Review Expert(s) Göran Selander, Derek Atkins, Sean Turner Reference [RFC-ietf-cose-rfc8152bis-algs-12] Available Formats [IMG] CSV Name Algorithm Label Type Description Reference Unassigned -65536 to -27 direct+HKDF-SHA-256, direct+HKDF-SHA-512, direct+HKDF-AES-128, direct+HKDF-AES-256, ECDH-ES+HKDF-256, ECDH-ES+HKDF-512, Party V other PartyV other ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, -26 bstr provided information [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW, ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW direct+HKDF-SHA-256, direct+HKDF-SHA-512, direct+HKDF-AES-128, direct+HKDF-AES-256, ECDH-ES+HKDF-256, ECDH-ES+HKDF-512, Party V provided PartyV nonce ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, -25 bstr / int nonce [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW, ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW direct+HKDF-SHA-256, direct+HKDF-SHA-512, direct+HKDF-AES-128, direct+HKDF-AES-256, ECDH-ES+HKDF-256, ECDH-ES+HKDF-512, Party V identity PartyV identity ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, -24 bstr information [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW, ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW direct+HKDF-SHA-256, direct+HKDF-SHA-512, direct+HKDF-AES-128, direct+HKDF-AES-256, ECDH-ES+HKDF-256, ECDH-ES+HKDF-512, Party U other PartyU other ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, -23 bstr provided information [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW, ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW direct+HKDF-SHA-256, direct+HKDF-SHA-512, direct+HKDF-AES-128, direct+HKDF-AES-256, ECDH-ES+HKDF-256, ECDH-ES+HKDF-512, Party U provided PartyU nonce ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, -22 bstr / int nonce [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW, ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW direct+HKDF-SHA-256, direct+HKDF-SHA-512, direct+HKDF-AES-128, direct+HKDF-AES-256, ECDH-ES+HKDF-256, ECDH-ES+HKDF-512, Party U identity PartyU identity ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, -21 bstr information [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW, ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW direct+HKDF-SHA-256, direct+HKDF-SHA-512, direct+HKDF-AES-128, direct+HKDF-AES-256, ECDH-ES+HKDF-256, ECDH-ES+HKDF-512, salt ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, -20 bstr Random salt [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW, ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW Unassigned -19 to -4 ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, Static public key static key id ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW -3 bstr identifier for the [RFC-ietf-cose-rfc8152bis-algs-12] sender static key ECDH-SS+HKDF-256, ECDH-SS+HKDF-512, -2 COSE_Key Static public key for [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-SS+A128KW, ECDH-SS+A192KW, ECDH-SS+A256KW the sender ephemeral key ECDH-ES+HKDF-256, ECDH-ES+HKDF-512, -1 COSE_Key Ephemeral public key [RFC-ietf-cose-rfc8152bis-algs-12] ECDH-ES+A128KW, ECDH-ES+A192KW, ECDH-ES+A256KW for the sender COSE Algorithms Expert(s) Göran Selander, Derek Atkins, Sean Turner Reference [RFC-ietf-cose-rfc8152bis-algs-12][RFC-ietf-cose-hash-algs-09] Available Formats [IMG] CSV Range Registration Procedures Integer values from -65536 to -257 Specification Required Integer values between -256 and 255 Standards Action With Expert Review Integer values from 256 to 65535 Specification Required Integer values greater than 65535 Expert Review Strings of length 1 Standards Action With Expert Review Strings of length 2 Specification Required Strings of length greater than 2 Expert Review Name Value Description Capabilities Change Reference Recommended Controller Reserved for Private less Use than [RFC-ietf-cose-rfc8152bis-algs-12] No -65536 Unassigned -65536 RS1 -65535 RSASSA-PKCS1-v1_5 [kty] IESG [RFC8812][RFC-ietf-cose-rfc8152bis-algs-12] Deprecated using SHA-1 -65534 Unassigned to -261 WalnutDSA -260 WalnutDSA [kty] [RFC9021] No signature RS512 -259 RSASSA-PKCS1-v1_5 [kty] IESG [RFC8812][RFC-ietf-cose-rfc8152bis-algs-12] No using SHA-512 RS384 -258 RSASSA-PKCS1-v1_5 [kty] IESG [RFC8812][RFC-ietf-cose-rfc8152bis-algs-12] No using SHA-384 RS256 -257 RSASSA-PKCS1-v1_5 [kty] IESG [RFC8812][RFC-ietf-cose-rfc8152bis-algs-12] No using SHA-256 Unassigned -256 to -48 ECDSA using ES256K -47 secp256k1 curve [kty] IESG [RFC8812][RFC-ietf-cose-rfc8152bis-algs-12] No and SHA-256 HSS/LMS HSS-LMS -46 hash-based [kty] [RFC8778][RFC-ietf-cose-rfc8152bis-algs-12] Yes digital signature SHAKE256 -45 SHAKE-256 512-bit [kty] [RFC-ietf-cose-hash-algs-09][RFC-ietf-cose-rfc8152bis-algs-12] Yes Hash Value SHA-512 -44 SHA-2 512-bit [kty] [RFC-ietf-cose-hash-algs-09][RFC-ietf-cose-rfc8152bis-algs-12] Yes Hash SHA-384 -43 SHA-2 384-bit [kty] [RFC-ietf-cose-hash-algs-09][RFC-ietf-cose-rfc8152bis-algs-12] Yes Hash RSAES-OAEP w/ -42 RSAES-OAEP w/ [kty] [RFC8230][RFC-ietf-cose-rfc8152bis-algs-12] Yes SHA-512 SHA-512 RSAES-OAEP w/ -41 RSAES-OAEP w/ [kty] [RFC8230][RFC-ietf-cose-rfc8152bis-algs-12] Yes SHA-256 SHA-256 RSAES-OAEP w/ RFC RSAES-OAEP w/ 8017 default -40 SHA-1 [kty] [RFC8230][RFC-ietf-cose-rfc8152bis-algs-12] Yes parameters PS512 -39 RSASSA-PSS w/ [kty] [RFC8230][RFC-ietf-cose-rfc8152bis-algs-12] Yes SHA-512 PS384 -38 RSASSA-PSS w/ [kty] [RFC8230][RFC-ietf-cose-rfc8152bis-algs-12] Yes SHA-384 PS256 -37 RSASSA-PSS w/ [kty] [RFC8230][RFC-ietf-cose-rfc8152bis-algs-12] Yes SHA-256 ES512 -36 ECDSA w/ SHA-512 [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes ES384 -35 ECDSA w/ SHA-384 [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes ECDH SS w/ Concat ECDH-SS + A256KW -34 KDF and AES Key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes Wrap w/ 256-bit key ECDH SS w/ Concat ECDH-SS + A192KW -33 KDF and AES Key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes Wrap w/ 192-bit key ECDH SS w/ Concat ECDH-SS + A128KW -32 KDF and AES Key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes Wrap w/ 128-bit key ECDH ES w/ Concat ECDH-ES + A256KW -31 KDF and AES Key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes Wrap w/ 256-bit key ECDH ES w/ Concat ECDH-ES + A192KW -30 KDF and AES Key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes Wrap w/ 192-bit key ECDH ES w/ Concat ECDH-ES + A128KW -29 KDF and AES Key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes Wrap w/ 128-bit key ECDH SS w/ HKDF - ECDH-SS + HKDF-512 -28 generate key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes directly ECDH SS w/ HKDF - ECDH-SS + HKDF-256 -27 generate key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes directly ECDH ES w/ HKDF - ECDH-ES + HKDF-512 -26 generate key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes directly ECDH ES w/ HKDF - ECDH-ES + HKDF-256 -25 generate key [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes directly Unassigned -24 to -19 SHAKE128 -18 SHAKE-128 256-bit [kty] [RFC-ietf-cose-hash-algs-09][RFC-ietf-cose-rfc8152bis-algs-12] Yes Hash Value SHA-2 512-bit SHA-512/256 -17 Hash truncated to [kty] [RFC-ietf-cose-hash-algs-09][RFC-ietf-cose-rfc8152bis-algs-12] Yes 256-bits SHA-256 -16 SHA-2 256-bit [kty] [RFC-ietf-cose-hash-algs-09][RFC-ietf-cose-rfc8152bis-algs-12] Yes Hash SHA-2 256-bit SHA-256/64 -15 Hash truncated to [kty] [RFC-ietf-cose-hash-algs-09][RFC-ietf-cose-rfc8152bis-algs-12] Filter Only 64-bits SHA-1 -14 SHA-1 Hash [kty] [RFC-ietf-cose-hash-algs-09][RFC-ietf-cose-rfc8152bis-algs-12] Filter Only Shared secret w/ direct+HKDF-AES-256 -13 AES-MAC 256-bit [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes key Shared secret w/ direct+HKDF-AES-128 -12 AES-MAC 128-bit [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes key direct+HKDF-SHA-512 -11 Shared secret w/ [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes HKDF and SHA-512 direct+HKDF-SHA-256 -10 Shared secret w/ [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes HKDF and SHA-256 Unassigned -9 EdDSA -8 EdDSA [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes ES256 -7 ECDSA w/ SHA-256 [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes direct -6 Direct use of CEK [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes A256KW -5 AES Key Wrap w/ [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 256-bit key A192KW -4 AES Key Wrap w/ [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 192-bit key A128KW -3 AES Key Wrap w/ [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit key Unassigned -2 to -1 Reserved 0 [RFC-ietf-cose-rfc8152bis-algs-12] No AES-GCM mode w/ A128GCM 1 128-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit tag AES-GCM mode w/ A192GCM 2 192-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit tag AES-GCM mode w/ A256GCM 3 256-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit tag HMAC w/ SHA-256 HMAC 256/64 4 truncated to 64 [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes bits HMAC 256/256 5 HMAC w/ SHA-256 [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes HMAC 384/384 6 HMAC w/ SHA-384 [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes HMAC 512/512 7 HMAC w/ SHA-512 [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes Unassigned 8-9 AES-CCM mode AES-CCM-16-64-128 10 128-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 64-bit tag, 13-byte nonce AES-CCM mode AES-CCM-16-64-256 11 256-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 64-bit tag, 13-byte nonce AES-CCM mode AES-CCM-64-64-128 12 128-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 64-bit tag, 7-byte nonce AES-CCM mode AES-CCM-64-64-256 13 256-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 64-bit tag, 7-byte nonce AES-MAC 128/64 14 AES-MAC 128-bit [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes key, 64-bit tag AES-MAC 256/64 15 AES-MAC 256-bit [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes key, 64-bit tag Unassigned 16-23 ChaCha20/Poly1305 ChaCha20/Poly1305 24 w/ 256-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit tag AES-MAC 128/128 25 AES-MAC 128-bit [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes key, 128-bit tag AES-MAC 256/128 26 AES-MAC 256-bit [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes key, 128-bit tag Unassigned 27-29 AES-CCM mode AES-CCM-16-128-128 30 128-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit tag, 13-byte nonce AES-CCM mode AES-CCM-16-128-256 31 256-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit tag, 13-byte nonce AES-CCM mode AES-CCM-64-128-128 32 128-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit tag, 7-byte nonce AES-CCM mode AES-CCM-64-128-256 33 256-bit key, [kty] [RFC-ietf-cose-rfc8152bis-algs-12] Yes 128-bit tag, 7-byte nonce For doing IV IV-GENERATION 34 generation for [RFC-ietf-cose-rfc8152bis-algs-12] No symmetric algorithms. COSE Key Common Parameters Expert(s) Francesca Palombini, Matt Miller, Justin Richer, Carsten Bormann Reference [RFC-ietf-cose-rfc8152bis-struct-15] Available Formats [IMG] CSV Range Registration Procedures Integer values in the range -65536 to -1 used for key parameters specific to a single algorithm delegated to the COSE Key Type Parameters registry Integer values between 0 and 255 Standards Action With Expert Review Integer values from 256 to 65535 Specification Required Integer values greater than 65535 Expert Review Strings of length 1 Standards Action With Expert Review Strings of length 2 Specification Required Strings of length greater than 2 Expert Review Name Label CBOR Type Value Registry Description Reference Reserved for Private Use less than [RFC-ietf-cose-rfc8152bis-struct-15] -65536 used for key parameters specific to a single algorithm delegated to the -65536 to -1 [RFC-ietf-cose-rfc8152bis-struct-15] COSE Key Type Parameters registry Reserved 0 [RFC-ietf-cose-rfc8152bis-struct-15] kty 1 tstr / int COSE Key Types Identification of the key [RFC-ietf-cose-rfc8152bis-struct-15] type kid 2 bstr Key identification value - [RFC-ietf-cose-rfc8152bis-struct-15] match to kid in message alg 3 tstr / int COSE Algorithms Key usage restriction to [RFC-ietf-cose-rfc8152bis-struct-15] this algorithm key_ops 4 [+ (tstr/int)] Restrict set of permissible [RFC-ietf-cose-rfc8152bis-struct-15] operations Base IV 5 bstr Base IV to be XORed with [RFC-ietf-cose-rfc8152bis-struct-15] Partial IVs COSE Key Type Parameters Registration Procedure(s) Expert Review Expert(s) Göran Selander, Derek Atkins, Sean Turner Reference [RFC-ietf-cose-rfc8152bis-algs-12] Available Formats [IMG] CSV Key Type Name Label CBOR Type Description Reference 1 crv -1 int / tstr EC identifier - Taken from the "COSE Elliptic Curves" [RFC-ietf-cose-rfc8152bis-algs-12] registry 1 x -2 bstr x-coordinate [RFC-ietf-cose-rfc8152bis-algs-12] 1 d -4 bstr Private key [RFC-ietf-cose-rfc8152bis-algs-12] 2 crv -1 int / tstr EC identifier - Taken from the "COSE Elliptic Curves" [RFC-ietf-cose-rfc8152bis-algs-12] registry 2 x -2 bstr Public Key [RFC-ietf-cose-rfc8152bis-algs-12] 2 y -3 bstr / bool y-coordinate [RFC-ietf-cose-rfc8152bis-algs-12] 2 d -4 bstr Private key [RFC-ietf-cose-rfc8152bis-algs-12] 3 n -1 bstr the RSA modulus n [RFC8230] 3 e -2 bstr the RSA public exponent e [RFC8230] 3 d -3 bstr the RSA private exponent d [RFC8230] 3 p -4 bstr the prime factor p of n [RFC8230] 3 q -5 bstr the prime factor q of n [RFC8230] 3 dP -6 bstr dP is d mod (p - 1) [RFC8230] 3 dQ -7 bstr dQ is d mod (q - 1) [RFC8230] 3 qInv -8 bstr qInv is the CRT coefficient q^(-1) mod p [RFC8230] 3 other -9 array other prime infos, an array [RFC8230] 3 r_i -10 bstr a prime factor r_i of n, where i >= 3 [RFC8230] 3 d_i -11 bstr d_i = d mod (r_i - 1) [RFC8230] 3 t_i -12 bstr the CRT coefficient t_i = (r_1 * r_2 * ... * [RFC8230] r_(i-1))^(-1) mod r_i 4 k -1 bstr Key Value [RFC-ietf-cose-rfc8152bis-algs-12] 5 pub -1 bstr Public key for HSS/LMS hash-based digital signature [RFC8778] 6 N -1 uint Group and Matrix (NxN) size [RFC9021] 6 q -2 uint Finite field F_q [RFC9021] 6 t-values -3 array (of uint) List of T-values, entries in F_q [RFC9021] 6 matrix 1 -4 array (of array of uint) NxN Matrix of entries in F_q in column-major form [RFC9021] 6 permutation 1 -5 array (of uint) Permutation associated with matrix 1 [RFC9021] 6 matrix 2 -6 array (of array of uint) NxN Matrix of entries in F_q in column-major form [RFC9021] COSE Key Types Registration Procedure(s) Expert Review Expert(s) Göran Selander, Derek Atkins, Sean Turner Reference [RFC-ietf-cose-rfc8152bis-algs-12] Available Formats [IMG] CSV Name Value Description Capabilities Reference Reserved 0 This value is reserved [RFC-ietf-cose-rfc8152bis-algs-12] OKP 1 Octet Key Pair [kty(1), crv] [RFC-ietf-cose-rfc8152bis-algs-12] EC2 2 Elliptic Curve Keys w/ x- and y-coordinate pair [kty(2), crv] [RFC-ietf-cose-rfc8152bis-algs-12] RSA 3 RSA Key [kty(3)] [RFC8230][RFC-ietf-cose-rfc8152bis-algs-12] Symmetric 4 Symmetric Keys [kty(4)] [RFC-ietf-cose-rfc8152bis-algs-12] HSS-LMS 5 Public key for HSS/LMS hash-based digital signature [kty(5), hash algorithm] [RFC8778][RFC-ietf-cose-rfc8152bis-algs-12] WalnutDSA 6 WalnutDSA public key [kty(6)] [RFC9021] COSE Elliptic Curves Expert(s) Göran Selander, Derek Atkins, Sean Turner Reference [RFC-ietf-cose-rfc8152bis-algs-12] Available Formats [IMG] CSV Range Registration Procedures Integer values -65536 to -257 Specification Required Integer values -256 to 255 Standards Action With Expert Review Integer values 256 to 65535 Specification Required Integer values greater than 65535 Expert Review Name Value Key Type Description Change Controller Reference Recommended Reserved for Private Integer values less [RFC-ietf-cose-rfc8152bis-algs-12] No Use than -65536 Unassigned -65536 to -1 Reserved 0 [RFC-ietf-cose-rfc8152bis-algs-12] No P-256 1 EC2 NIST P-256 also known as [RFC-ietf-cose-rfc8152bis-algs-12] Yes secp256r1 P-384 2 EC2 NIST P-384 also known as [RFC-ietf-cose-rfc8152bis-algs-12] Yes secp384r1 P-521 3 EC2 NIST P-521 also known as [RFC-ietf-cose-rfc8152bis-algs-12] Yes secp521r1 X25519 4 OKP X25519 for use w/ ECDH only [RFC-ietf-cose-rfc8152bis-algs-12] Yes X448 5 OKP X448 for use w/ ECDH only [RFC-ietf-cose-rfc8152bis-algs-12] Yes Ed25519 6 OKP Ed25519 for use w/ EdDSA only [RFC-ietf-cose-rfc8152bis-algs-12] Yes Ed448 7 OKP Ed448 for use w/ EdDSA only [RFC-ietf-cose-rfc8152bis-algs-12] Yes secp256k1 8 EC2 SECG secp256k1 curve IESG [RFC8812] No