OpenPGP

Created
2024-01-19
Last Updated
2026-07-02
Available Formats

XML
HTML
TXT

Registries Included Below

OpenPGP String-to-Key (S2K) Types

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
ID S2K Type S2K Field Size (Octets) Generate? Reference
0 Simple S2K 2 No [RFC9580, Section 3.7.1.1]
1 Salted S2K 10 Only when string is high entropy [RFC9580, Section 3.7.1.2]
2 Reserved value No [RFC 9580]
3 Iterated and Salted S2K 11 Yes [RFC9580, Section 3.7.1.3]
4 Argon2 20 Yes [RFC9580, Section 3.7.1.4]
5-99 Unassigned
100-110 Private or Experimental Use As appropriate [RFC 9580]
111-255 Unassigned

OpenPGP Packet Types

Registration Procedure(s)
RFC Required
Reference
[RFC 9580]
Available Formats

CSV
ID Critical Packet Type Description Shorthand Reference
0 Yes Reserved - this Packet Type ID MUST NOT be used [RFC 9580]
1 Yes Public Key Encrypted Session Key Packet PKESK [RFC9580, Section 5.1]
2 Yes Signature Packet SIG [RFC9580, Section 5.2]
3 Yes Symmetric Key Encrypted Session Key Packet SKESK [RFC9580, Section 5.3]
4 Yes One-Pass Signature Packet OPS [RFC9580, Section 5.4]
5 Yes Secret Key Packet SECKEY [RFC9580, Section 5.5.1.3]
6 Yes Public Key Packet PUBKEY [RFC9580, Section 5.5.1.1]
7 Yes Secret Subkey Packet SECSUBKEY [RFC9580, Section 5.5.1.4]
8 Yes Compressed Data Packet COMP [RFC9580, Section 5.6]
9 Yes Symmetrically Encrypted Data Packet SED [RFC9580, Section 5.7]
10 Yes Marker Packet MARKER [RFC9580, Section 5.8]
11 Yes Literal Data Packet LIT [RFC9580, Section 5.9]
12 Yes Trust Packet TRUST [RFC9580, Section 5.10]
13 Yes User ID Packet UID [RFC9580, Section 5.11]
14 Yes Public Subkey Packet PUBSUBKEY [RFC9580, Section 5.5.1.2]
15-16 Unassigned
17 Yes User Attribute Packet UAT [RFC9580, Section 5.12]
18 Yes Symmetrically Encrypted and Integrity Protected Data Packet SEIPD [RFC9580, Section 5.13]
19 Yes Reserved (formerly Modification Detection Code Packet) [RFC9580, Section 5.13.1]
20 Yes Reserved [RFC 9580]
21 Yes Padding Packet PADDING [RFC9580, Section 5.14]
22-39 Yes Unassigned Critical Packets
40-59 No Unassigned Non-Critical Packets
60-63 No Private or Experimental Use [RFC 9580]

OpenPGP User Attribute Subpacket Types

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
ID Attribute Subpacket Reference
0 Reserved [RFC 9580]
1 Image Attribute Subpacket [RFC9580, Section 5.12.1]
2-99 Unassigned
100-110 Private or Experimental Use [RFC 9580]
111-255 Unassigned

OpenPGP Image Attribute Encoding Format

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
ID Encoding Reference
0 Reserved [RFC 9580]
1 JPEG [JFIF] [RFC 9580]
2-99 Unassigned
100-110 Private or Experimental Use [RFC 9580]
111-255 Unassigned

OpenPGP Signature Subpacket Types

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
ID Description Reference
0 Reserved [RFC 9580]
1 Reserved [RFC 9580]
2 Signature Creation Time [RFC9580, Section 5.2.3.11]
3 Signature Expiration Time [RFC9580, Section 5.2.3.18]
4 Exportable Certification [RFC9580, Section 5.2.3.19]
5 Trust Signature [RFC9580, Section 5.2.3.21]
6 Regular Expression [RFC9580, Section 5.2.3.22]
7 Revocable [RFC9580, Section 5.2.3.20]
8 Reserved [RFC 9580]
9 Key Expiration Time [RFC9580, Section 5.2.3.13]
10 Placeholder for backward compatibility [RFC 9580]
11 Preferred Symmetric Ciphers for v1 SEIPD [RFC9580, Section 5.2.3.14]
12 Revocation Key (deprecated) [RFC9580, Section 5.2.3.23]
13-15 Reserved [RFC 9580]
16 Issuer Key ID [RFC9580, Section 5.2.3.12]
17-19 Reserved [RFC 9580]
20 Notation Data [RFC9580, Section 5.2.3.24]
21 Preferred Hash Algorithms [RFC9580, Section 5.2.3.16]
22 Preferred Compression Algorithms [RFC9580, Section 5.2.3.17]
23 Key Server Preferences [RFC9580, Section 5.2.3.25]
24 Preferred Key Server [RFC9580, Section 5.2.3.26]
25 Primary User ID [RFC9580, Section 5.2.3.27]
26 Policy URI [RFC9580, Section 5.2.3.28]
27 Key Flags [RFC9580, Section 5.2.3.29]
28 Signer's User ID [RFC9580, Section 5.2.3.30]
29 Reason for Revocation [RFC9580, Section 5.2.3.31]
30 Features [RFC9580, Section 5.2.3.32]
31 Signature Target [RFC9580, Section 5.2.3.33]
32 Embedded Signature [RFC9580, Section 5.2.3.34]
33 Issuer Fingerprint [RFC9580, Section 5.2.3.35]
34 Reserved [RFC 9580]
35 Intended Recipient Fingerprint [RFC9580, Section 5.2.3.36]
37 Reserved (Attested Certifications) [RFC 9580]
38 Reserved (Key Block) [RFC 9580]
39 Preferred AEAD Ciphersuites [RFC9580, Section 5.2.3.15]
40-99 Unassigned
100-110 Private or Experimental Use [RFC 9580]
111-127 Unassigned

OpenPGP Key Server Preference Flags

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Note
This is a variable length bit field.
Available Formats

CSV
Flag Shorthand Definition Reference
0x80... No-modify The keyholder requests that this key only be modified or updated by the keyholder or an administrator of the key server. [RFC 9580]

OpenPGP Reason for Revocation (Revocation Octet)

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Code Reason Reference
0 No reason specified (Key Revocation or Certification Revocation signatures) [RFC 9580]
1 Key is superseded (Key Revocation signatures) [RFC 9580]
2 Key material has been compromised (Key Revocation signatures) [RFC 9580]
3 Key is retired and no longer used (Key Revocation signatures) [RFC 9580]
4-31 Unassigned
32 User ID information is no longer valid (Certification Revocation signatures) [RFC 9580]
33-99 Unassigned
100-110 Private Use [RFC 9580]

OpenPGP Features Flags

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Note
This is a variable length bit field.
Available Formats

CSV
Feature Definition Reference
0x01... Version 1 Symmetrically Encrypted and Integrity Protected Data packet [RFC9580, Section 5.13.1]
0x02... Reserved [RFC 9580]
0x04... Reserved [RFC 9580]
0x08... Version 2 Symmetrically Encrypted and Integrity Protected Data packet [RFC9580, Section 5.13.2]

OpenPGP New Packet Versions (OBSOLETE)

Registration Procedure(s)
Registry closed
Reference
[RFC 9580]
Note
Those wishing to use the removed "New Packet Versions" registry 
should instead register new versions of the relevant packets in the 
"OpenPGP Key and Signature Versions", "OpenPGP Key IDs and 
Fingerprints", and "OpenPGP Encrypted Message Packet Versions" 
registries.
No registrations at this time.

OpenPGP Key Flags

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Note
This is a variable length bit field.
Available Formats

CSV
Flag Definition Reference
0x01... This key may be used to make User ID certifications (Signature Type IDs 0x10-0x13) or Direct Key signatures (Signature Type ID 0x1F) over other keys. [RFC 9580]
0x02... This key may be used to sign data. [RFC 9580]
0x04... This key may be used to encrypt communications. [RFC 9580]
0x08... This key may be used to encrypt storage. [RFC 9580]
0x10... The private component of this key may have been split by a secret-sharing mechanism. [RFC 9580]
0x20... This key may be used for authentication. [RFC 9580]
0x80... The private component of this key may be in the possession of more than one person. [RFC 9580]
0x0004... Reserved (ADSK) [RFC 9580]
0x0008... Reserved (timestamping) [RFC 9580]

OpenPGP Public Key Algorithms

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Note
The field specifications enclosed in square brackets
for PKESK Format represent fields that may or may not be present,
depending on the PKESK version.
Available Formats

CSV
ID Algorithm Public Key Format Secret Key Format Signature Format PKESK Format Reference
0 Reserved [RFC 9580]
1 RSA (Encrypt or Sign) [FIPS186] MPI(n), MPI(e) [RFC9580, Section 5.5.5.1] MPI(d), MPI(p), MPI(q), MPI(u) MPI(m^d mod n) [RFC9580, Section 5.2.3.1] MPI(m^e mod n) [RFC9580, Section 5.1.3] [RFC 9580]
2 RSA Encrypt-Only [FIPS186] MPI(n), MPI(e) [RFC9580, Section 5.5.5.1] MPI(d), MPI(p), MPI(q), MPI(u) N/A MPI(m^e mod n) [RFC9580, Section 5.1.3] [RFC 9580]
3 RSA Sign-Only [FIPS186] MPI(n), MPI(e) [RFC9580, Section 5.5.5.1] MPI(d), MPI(p), MPI(q), MPI(u) MPI(m^d mod n) [RFC9580, Section 5.2.3.1] N/A [RFC 9580]
4-15 Unassigned
16 Elgamal (Encrypt-Only) [ELGAMAL] MPI(p), MPI(g), MPI(y) [RFC9580, Section 5.5.5.3] MPI(x) N/A MPI(g^k mod p), MPI(m * y^k mod p) [RFC9580, Section 5.1.4] [RFC 9580]
17 DSA (Digital Signature Algorithm) [FIPS186] MPI(p), MPI(q), MPI(g), MPI(y) [RFC9580, Section 5.5.5.2] MPI(x) MPI(r), MPI(s) [RFC9580, Section 5.2.3.2] N/A [RFC 9580]
18 ECDH public key algorithm OID, MPI(point in curve-specific point format), KDFParams [RFC9580, Sections 9.2.1 and 5.5.5.6] MPI(value in curve-specific format) [RFC9580, Section 9.2.1] N/A MPI(point in curve-specific point format), size octet, encoded key [RFC9580, Sections 9.2.1, 5.1.5, and 11.5] [RFC 9580]
19 ECDSA public key algorithm [FIPS186] OID, MPI(point in SEC1 format) [RFC9580, Section 5.5.5.4] MPI(value) MPI(r), MPI(s) [RFC9580, Section 5.2.3.2] N/A [RFC 9580]
20 Reserved (formerly Elgamal Encrypt or Sign) [RFC 9580]
21 Reserved for Diffie-Hellman (X9.42, as defined for IETF-S/MIME) [RFC 9580]
22 EdDSALegacy (deprecated) OID, MPI(point in prefixed native format) [RFC9580, Sections 11.2.2 and 5.5.5.5] MPI(value in curve-specific format) [RFC9580, Section 9.2.1] MPI, MPI [RFC9580, Sections 9.2.1 and 5.2.3.3] N/A [RFC 9580]
23 Reserved (AEDH) [RFC 9580]
24 Reserved (AEDSA) [RFC 9580]
25 X25519 32 octets [RFC9580, Section 5.5.5.7] 32 octets N/A 32 octets, size octet, encoded key [RFC9580, Section 5.1.6] [RFC 9580]
26 X448 56 octets [RFC9580, Section 5.5.5.8] 56 octets N/A 56 octets, size octet, encoded key [RFC9580, Section 5.1.7] [RFC 9580]
27 Ed25519 32 octets [RFC9580, Section 5.5.5.9] 32 octets 64 octets [RFC9580, Section 5.2.3.4] [RFC 9580]
28 Ed448 57 octets [RFC9580, Section 5.5.5.10] 57 octets 114 octets [RFC9580, Section 5.2.3.5] [RFC 9580]
29 Unassigned
30 ML-DSA-65+Ed25519 32-octet Ed25519 public key [Table 6], 1952-octet ML-DSA-65 public key [Table 7] 32-octet Ed25519 secret key [Table 6], 32-octet ML-DSA-65 secret key [Table 7] 64-octet Ed25519 signature [Table 6], 3309-octet ML-DSA-65 signature [Table 7] N/A [RFC 9980, Section 5]
31 ML-DSA-87+Ed448 57-octet Ed448 public key [Table 6], 2592-octet ML-DSA-87 public key [Table 7] 57-octet Ed448 secret key [Table 6], 32-octet ML-DSA-87 secret key [Table 7] 114-octet Ed448 signature [Table 6], 4627-octet ML-DSA-87 signature [Table 7] N/A [RFC 9980, Section 5]
32 SLH-DSA-SHAKE-128s 32-octet public key [Table 8] 64-octet secret key [Table 8] 7856-octet signature [Table 8] N/A [RFC 9980, Section 6.1]
33 SLH-DSA-SHAKE-128f 32-octet public key [Table 8] 64-octet secret key [Table 8] 17088-octet signature [Table 8] N/A [RFC 9980, Section 6.1]
34 SLH-DSA-SHAKE-256s 64-octet public key [Table 8] 128-octet secret key [Table 8] 29792-octet signature [Table 8] N/A [RFC 9980, Section 6.1]
35 ML-KEM-768+X25519 32-octet X25519 public key [Table 3], 1184-octet ML-KEM-768 public key [Table 4] 32-octet X25519 secret key [Table 3], 64-octet ML-KEM-768 secret key [Table 4] N/A 32-octet X25519 ciphertext, 1088-octet ML-KEM-768 ciphertext, 1 octet remaining length, [1-octet algorithm ID in the case of v3 PKESK,] n octets wrapped session key [RFC 9980, Section 4.3.1] [RFC 9980, Section 4]
36 ML-KEM-1024+X448 56-octet X448 public key [Table 3], 1568-octet ML-KEM-1024 public key [Table 4] 56-octet X448 secret key [Table 3], 64-octet ML-KEM-1024 secret key [Table 4] N/A 56-octet X448 ciphertext, 1568-octet ML-KEM-1024 ciphertext, 1 octet remaining length, [1-octet algorithm ID in the case of v3 PKESK,] n octets wrapped session key [RFC 9980, Section 4.3.1] [RFC 9980, Section 4]
37-99 Unassigned
100-110 Private or Experimental Use
111-255 Unassigned

OpenPGP Symmetric Key Algorithms

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Note
When registering a new symmetric cipher with a block size of 64 or
128 bits and a key size that is a multiple of 64 bits, no new
considerations are needed.

If the new cipher has a different block size, there needs to be
additional documentation describing how to use the cipher in CFB
mode.

If the new cipher has an unusual key size, then padding needs to be
considered for X25519 and X448 key wrapping, which currently needs no
padding.
Available Formats

CSV
ID Algorithm Reference
0 Plaintext or unencrypted data [RFC 9580]
1 IDEA [IDEA] [RFC 9580]
2 TripleDES (or DES-EDE) [SP800-67] with 168-bit key derived from 192 [RFC 9580]
3 CAST5 with 128-bit key [RFC 2144] [RFC 9580]
4 Blowfish with 128-bit key, 16 rounds [BLOWFISH] [RFC 9580]
5 Reserved [RFC 9580]
6 Reserved [RFC 9580]
7 AES with 128-bit key [AES] [RFC 9580]
8 AES with 192-bit key [RFC 9580]
9 AES with 256-bit key [RFC 9580]
10 Twofish with 256-bit key [TWOFISH] [RFC 9580]
11 Camellia with 128-bit key [RFC 3713] [RFC 9580]
12 Camellia with 192-bit key [RFC 9580]
13 Camellia with 256-bit key [RFC 9580]
14-99 Unassigned
100-110 Private or Experimental Use [RFC 9580]
111-252 Unassigned
253-255 Reserved to avoid collision with Secret Key Encryption (see the [OpenPGP Secret Key Encryption (S2K Usage Octet)] registry and [RFC9580, Section 5.5.3]) [RFC 9580]

OpenPGP Hash Algorithms

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Note
When registering a new hash algorithm, if the algorithm is also to
be used with RSA signing schemes, it must also have an entry in the
"OpenPGP Hash Algorithm Identifiers for RSA Signatures' use of
EMSA-PKCS1-v1_5 Padding" registry.
Available Formats

CSV
ID Algorithm Text Name V6 Signature Salt Size Reference
0 Reserved [RFC 9580]
1 MD5 [RFC 1321] "MD5" N/A [RFC 9580]
2 SHA-1 [FIPS180] "SHA1" N/A [RFC 9580]
3 RIPEMD-160 [RIPEMD-160] "RIPEMD160" N/A [RFC 9580]
4-7 Reserved [RFC 9580]
8 SHA2-256 [FIPS180] "SHA256" 16 [RFC 9580]
9 SHA2-384 [FIPS180] "SHA384" 24 [RFC 9580]
10 SHA2-512 [FIPS180] "SHA512" 32 [RFC 9580]
11 SHA2-224 [FIPS180] "SHA224" 16 [RFC 9580]
12 SHA3-256 [FIPS202] "SHA3-256" 16 [RFC 9580]
13 Reserved [RFC 9580]
14 SHA3-512 [FIPS202] "SHA3-512" 32 [RFC 9580]
15-99 Unassigned
100-110 Private or Experimental Use [RFC 9580]
111-255 Unassigned

OpenPGP Compression Algorithms

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
ID Algorithm Reference
0 Uncompressed [RFC 9580]
1 ZIP [RFC 1951] [RFC 9580]
2 ZLIB [RFC 1950] [RFC 9580]
3 BZip2 [BZ2] [RFC 9580]
4-99 Unassigned [RFC 9580]
100-110 Private or Experimental Use [RFC 9580]
111-255 Unassigned [RFC 9580]

OpenPGP Secret Key Encryption (S2K Usage Octet)

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
S2K Usage Octet Shorthand Encryption Parameter Fields Encryption Generate? Reference
0 Unprotected - v3 or v4 keys: [cleartext secrets || check(secrets)] v6 keys: [cleartext secrets] Yes [RFC 9580]
Known symmetric cipher algo ID (see [RFC9580, Section 9.3]) LegacyCFB IV CFB(MD5(passphrase), secrets || check(secrets)) No [RFC 9580]
253 AEAD params-length (v6-only), cipher-algo, AEAD-mode, S2K-specifier-length (v6-only), S2K-specifier, nonce AEAD(HKDF(S2K(passphrase), info), secrets, packetprefix) Yes [RFC 9580]
254 CFB params-length (v6-only), cipher-algo, S2K-specifier-length (v6-only), S2K-specifier, IV CFB(S2K(passphrase), secrets || SHA1(secrets)) Yes [RFC 9580]
255 MalleableCFB cipher-algo, S2K-specifier, IV CFB(S2K(passphrase), secrets || check(secrets)) No [RFC 9580]

OpenPGP Signature Types

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
ID Name Reference
0x00 Binary Signature [RFC9580, Section 5.2.1.1]
0x01 Text Signature [RFC9580, Section 5.2.1.2]
0x02 Standalone Signature [RFC9580, Section 5.2.1.3]
0x03-0x0F Unassigned
0x10 Generic Certification Signature [RFC9580, Section 5.2.1.4]
0x11 Persona Certification Signature [RFC9580, Section 5.2.1.5]
0x12 Casual Certification Signature [RFC9580, Section 5.2.1.6]
0x13 Positive Certification Signature [RFC9580, Section 5.2.1.7]
0x14-0x17 Unassigned
0x18 Subkey Binding Signature [RFC9580, Section 5.2.1.8]
0x19 Primary Key Binding Signature [RFC9580, Section 5.2.1.9]
0x1A-0x1E Unassigned
0x1F Direct Key Signature [RFC9580, Section 5.2.1.10]
0x20 Key Revocation Signature [RFC9580, Section 5.2.1.11]
0x21-0x27 Unassigned
0x28 Subkey Revocation Signature [RFC9580, Section 5.2.1.12]
0x29-0x2F Unassigned
0x30 Certification Revocation Signature [RFC9580, Section 5.2.1.13]
0x31-0x3F Unassigned
0x40 Timestamp Signature [RFC9580, Section 5.2.1.14]
0x41-0x4F Unassigned
0x50 Third-Party Confirmation Signature [RFC9580, Section 5.2.1.15]
0x51-0xFE Unassigned
0xFF Reserved [RFC9580, Section 5.2.1.16]

OpenPGP Signature Notation Data Subpacket Notation Flags

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Flag Position Shorthand Description Reference
0x80000000 (first bit of the first octet) human-readable Notation value is UTF-8 text [RFC 9580]

OpenPGP Signature Notation Data Subpacket Types

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Note
Notation names are arbitrary Unicode strings encoded in UTF-8. They
reside in two namespaces: the IETF namespace and the user namespace.

This registry documents the IETF namespace. The names in this
registry MUST NOT contain the "@" character (0x40), since the
presence of that character indicates the user namespace.
Notation Name Data Type Allowed Values Reference
No registrations at this time.

OpenPGP Key IDs and Fingerprints

Registration Procedure(s)
RFC Required
Reference
[RFC 9580]
Note
When a new key version is defined, the "OpenPGP Key and Signature
Versions" registry should also be updated.
Available Formats

CSV
Key Version Fingerprint Fingerprint Length (Bits) Key ID Reference
3 MD5(MPIs without length octets) 128 low 64 bits of RSA modulus [RFC9580, Section 5.5.4.1]
4 SHA1(normalized pubkey packet) 160 last 64 bits of fingerprint [RFC9580, Section 5.5.4.2]
6 SHA256(normalized pubkey packet) 256 first 64 bits of fingerprint [RFC9580, Section 5.5.4.3]

OpenPGP Image Attribute Versions

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Version Reference
1 [RFC9580, Section 5.12.1]

OpenPGP Armor Header Lines

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Armor Header Use Reference
BEGIN PGP MESSAGE Used for signed, encrypted, or compressed files. [RFC 9580]
BEGIN PGP PUBLIC KEY BLOCK Used for armoring public keys. [RFC 9580]
BEGIN PGP PRIVATE KEY BLOCK Used for armoring private keys. [RFC 9580]
BEGIN PGP SIGNATURE Used for detached signatures, OpenPGP/MIME signatures, and cleartext signatures. [RFC 9580]

OpenPGP Armor Header Keys

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Key Summary Reference
Version Implementation information [RFC9580, Section 6.2.2.1]
Comment Arbitrary text [RFC9580, Section 6.2.2.2]
Hash Hash algorithms used in some v4 cleartext signed messages [RFC9580, Section 6.2.2.3]
Charset Character set [RFC9580, Section 6.2.2.4]

OpenPGP ECC Curve OIDs and Usage

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Note
When a new elliptic curve is registered for use with OpenPGP, it
should also be added to the "OpenPGP ECC Curve-specific Wire
Formats" registry. If it is used for ECDH, also add it to the
"OpenPGP ECDH KDF and KEK Parameters" registry.
Available Formats

CSV
ASN.1 Object Identifier OID Len Curve OID Octets Curve Name Usage Field Size (fsize) Reference
1.2.840.10045.3.1.7 8 2A 86 48 CE 3D 03 01 07 NIST P-256 ECDSA, ECDH 32 [RFC 9580]
1.3.132.0.34 5 2B 81 04 00 22 NIST P-384 ECDSA, ECDH 48 [RFC 9580]
1.3.132.0.35 5 2B 81 04 00 23 NIST P-521 ECDSA, ECDH 66 [RFC 9580]
1.3.36.3.3.2.8.1.1.7 9 2B 24 03 03 02 08 01 01 07 brainpoolP256r1 ECDSA, ECDH 32 [RFC 9580]
1.3.36.3.3.2.8.1.1.11 9 2B 24 03 03 02 08 01 01 0B brainpoolP384r1 ECDSA, ECDH 48 [RFC 9580]
1.3.36.3.3.2.8.1.1.13 9 2B 24 03 03 02 08 01 01 0D brainpoolP512r1 ECDSA, ECDH 64 [RFC 9580]
1.3.6.1.4.1.11591.15.1 9 2B 06 01 04 01 DA 47 0F 01 Ed25519Legacy EdDSALegacy 32 [RFC 9580]
1.3.6.1.4.1.3029.1.5.1 10 2B 06 01 04 01 97 55 01 05 01 Curve25519Legacy ECDH 32 [RFC 9580]

OpenPGP ECC Curve-Specific Wire Formats

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Curve ECDH Point Format ECDH Secret Key MPI EdDSA Secret Key MPI EdDSA Signature first MPI EdDSA Signature second MPI Reference
NIST P-256 SEC1 integer N/A N/A N/A [RFC 9580]
NIST P-384 SEC1 integer N/A N/A N/A [RFC 9580]
NIST P-521 SEC1 integer N/A N/A N/A [RFC 9580]
brainpoolP256r1 SEC1 integer N/A N/A N/A [RFC 9580]
brainpoolP384r1 SEC1 integer N/A N/A N/A [RFC 9580]
brainpoolP512r1 SEC1 integer N/A N/A N/A [RFC 9580]
Ed25519Legacy N/A N/A 32 octets of secret 32 octets of R 32 octets of S [RFC 9580]
Curve25519Legacy prefixed native integer [RFC9580, Section 5.5.5.6.1.1] N/A N/A N/A [RFC 9580]

OpenPGP Hash Algorithm Identifiers for RSA Signatures' Use of EMSA-PKCS1-v1_5 Padding

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Hash Algorithm OID Full Hash Prefix Reference
MD5 1.2.840.113549.2.5 0x30, 0x20, 0x30, 0x0C, 0x06, 0x08, 0x2A, 0x86, 0x48, 0x86, 0xF7, 0x0D, 0x02, 0x05, 0x05, 0x00, 0x04, 0x10 [RFC 9580]
SHA-1 1.3.14.3.2.26 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2B, 0x0E, 0x03, 0x02, 0x1A, 0x05, 0x00, 0x04, 0x14 [RFC 9580]
RIPEMD-160 1.3.36.3.2.1 0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2B, 0x24, 0x03, 0x02, 0x01, 0x05, 0x00, 0x04, 0x14 [RFC 9580]
SHA2-256 2.16.840.1.101.3.4.2.1 0x30, 0x31, 0x30, 0x0D, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01, 0x05, 0x00, 0x04, 0x20 [RFC 9580]
SHA2-384 2.16.840.1.101.3.4.2.2 0x30, 0x41, 0x30, 0x0D, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02, 0x05, 0x00, 0x04, 0x30 [RFC 9580]
SHA2-512 2.16.840.1.101.3.4.2.3 0x30, 0x51, 0x30, 0x0D, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40 [RFC 9580]
SHA2-224 2.16.840.1.101.3.4.2.4 0x30, 0x2D, 0x30, 0x0D, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04, 0x05, 0x00, 0x04, 0x1C [RFC 9580]
SHA3-256 2.16.840.1.101.3.4.2.8 0x30, 0x31, 0x30, 0x0D, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x08, 0x05, 0x00, 0x04, 0x20 [RFC 9580]
SHA3-512 2.16.840.1.101.3.4.2.10 0x30, 0x51, 0x30, 0x0D, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x0a, 0x05, 0x00, 0x04, 0x40 [RFC 9580]

OpenPGP AEAD Algorithms

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
ID Name Nonce Length (Octets) Authentication Tag Length (Octets) Reference
0 Reserved [RFC 9580]
1 EAX [EAX] 16 16 [RFC 9580]
2 OCB [RFC 7253] 15 16 [RFC 9580]
3 GCM [SP800-38D] 12 16 [RFC 9580]
4-99 Unassigned
100-110 Private or Experimental Use [RFC 9580]
111-255 Unassigned

OpenPGP Encrypted Message Packet Versions

Registration Procedure(s)
RFC Required
Reference
[RFC 9580]
Note
When a new version of SEIPD, PKESK, or SKESK are defined, consider
also adding a corresponding flag to the "OpenPGP Features Flags"
registry.
Available Formats

CSV
Version of Encrypted Data Payload Version of Preceding Symmetric Key ESK (If Any) Version of Preceding Public Key ESK (If Any) Generate? Reference
SED [RFC9580, Section 5.7] - v2 PKESK [RFC 2440] No [RFC 9580]
SED [RFC9580, Section 5.7] v4 SKESK [RFC9580, Section 5.3.1] v3 PKESK [RFC9580, Section 5.1.1] No [RFC 9580]
v1 SEIPD [RFC9580, Section 5.13.1] v4 SKESK [RFC9580, Section 5.3.1] v3 PKESK [RFC9580, Section 5.1.1] Yes [RFC 9580]
v2 SEIPD [RFC9580, Section 5.13.2] v6 SKESK [RFC9580, Section 5.3.2] v6 PKESK [RFC9580, Section 5.1.2] Yes [RFC 9580]

OpenPGP Key and Signature Versions

Registration Procedure(s)
RFC Required
Reference
[RFC 9580]
Note
When a new key version is defined, the "OpenPGP Key IDs and
Fingerprints" registry should also be updated.
Available Formats

CSV
Signing Key Version Signature Packet Version OPS Packet Version Generate? Reference
3 [RFC9580, Section 5.5.2.1] 3 [RFC9580, Section 5.2.2] 3 [RFC9580, Section 5.4] No [RFC 9580]
4 [RFC9580, Section 5.5.2.2] 3 [RFC9580, Section 5.2.2] 3 [RFC9580, Section 5.4] No [RFC 9580]
4 [RFC9580, Section 5.5.2.2] 4 [RFC9580, Section 5.2.3] 3 [RFC9580, Section 5.4] Yes [RFC 9580]
6 [RFC9580, Section 5.5.2.3] 6 [RFC9580, Section 5.2.3] 6 [RFC9580, Section 5.4] Yes [RFC 9580]

OpenPGP Elliptic Curve Point Wire Formats

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Name Wire Format Reference
SEC1 0x04 || x || y [RFC9580, Section 11.2.1]
Prefixed native 0x40 || native [RFC9580, Section 11.2.2]

OpenPGP Elliptic Curve Scalar Encodings

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Type Description Reference
integer An integer encoded in big-endian format as a standard OpenPGP MPI [RFC9580, Section 3.2]
octet string An octet string of fixed length that may be shorter on the wire due to leading zeros being stripped by the MPI encoding and may need to be zero-padded before use [RFC9580, Section 11.3.1]
prefixed N octets An octet string of fixed length N, prefixed with octet 0x40 to ensure no leading zero octet [RFC9580, Section 11.3.2]

OpenPGP ECDH KDF and KEK Parameters

Registration Procedure(s)
Specification Required
Expert(s)
Daniel Kahn Gillmor, Andrew Gallagher, Heiko Schäfer
Reference
[RFC 9580]
Available Formats

CSV
Curve Hash Algorithm Symmetric Algorithm Reference
NIST P-256 SHA2-256 AES-128 [RFC 9580]
NIST P-384 SHA2-384 AES-192 [RFC 9580]
NIST P-521 SHA2-512 AES-256 [RFC 9580]
brainpoolP256r1 SHA2-256 AES-128 [RFC 9580]
brainpoolP384r1 SHA2-384 AES-192 [RFC 9580]
brainpoolP512r1 SHA2-512 AES-256 [RFC 9580]
Curve25519Legacy SHA2-256 AES-128 [RFC 9580]