]> NIST

USA quynh.dang@nist.gov

BSI

Germany stephan.ehlen@bsi.bund.de

MTG AG

Germany johannes.roth@mtg.de

MTG AG

Germany falko.strenzke@mtg.de

sec Network Working Group Internet-Draft This document defines PQ/T composite schemes based on ML-KEM and ML-DSA combined with ECC algorithms using the NIST and Brainpool domain parameters for the OpenPGP protocol. About This Document Status information for this document may be found at . Discussion of this document takes place on the WG Working Group mailing list (), which is archived at . Subscribe at . Source for this draft and an issue tracker can be found at .

Introduction This document defines PQ/T composite schemes based on ML-KEM and ML-DSA combined with ECDH and ECDSA using the NIST and Brainpool domain parameters for the OpenPGP protocol. As such it extends , which introduces post-quantum cryptography in OpenPGP. The ML-KEM and ML-DSA composite schemes defined in that document are built with ECC algorithms using the Edwards Curves defined in and . This document extends the set of algorithms given in by further combinations of ML-KEM and ML-DSA with the NIST and Brainpool domain parameters. The support of NIST and Brainpool domain parameters is required in various applications related to certain regulatory environments.

Conventions used in this Document

Terminology for Multi-Algorithm Schemes The terminology in this document is oriented towards the definitions in . Specifically, the terms "multi-algorithm", "composite" and "non-composite" are used in correspondence with the definitions therein. The abbreviation "PQ" is used for post-quantum schemes. To denote the combination of post-quantum and traditional schemes, the abbreviation "PQ/T" is used. The short form "PQ(/T)" stands for PQ or PQ/T.

Post-Quantum Cryptography This section describes the individual post-quantum cryptographic schemes. All schemes listed here are believed to provide security in the presence of a cryptographically relevant quantum computer. [Note to the reader: This specification refers to the NIST PQC draft standards FIPS 203 and FIPS 204 as if they were a final specification. This is a temporary solution until the final versions of these documents are available. The goal is to provide a sufficiently precise specification of the algorithms already at the draft stage of this specification, so that it is possible for implementers to create interoperable implementations. Furthermore, we want to point out that, depending on possible future changes to the draft standards by NIST, this specification may be updated as soon as corresponding information becomes available.]

ML-KEM ML-KEM is based on the hardness of solving the Learning with Errors problem in module lattices (MLWE). The scheme is believed to provide security against cryptanalytic attacks by classical as well as quantum computers. This specification defines ML-KEM only in composite combination with ECC-based encryption schemes in order to provide a pre-quantum security fallback.

ML-DSA ML-DSA is a signature scheme that, like ML-KEM, is based on the hardness of solving the Learning With Errors problem and a variant of the Short Integer Solution problem in module lattices (MLWE and SelfTargetMSIS). Accordingly, this specification only defines ML-DSA in composite combination with ECC-based signature schemes.

Elliptic Curve Cryptography The ECC-based encryption is defined here as a KEM. This is in contrast to where the ECC-based encryption is defined as a public-key encryption scheme. All elliptic curves for the use in the composite combinations are taken from . For interoperability this extension offers ML-* in composite combinations with the NIST curves P-256, P-384 defined in and the Brainpool curves brainpoolP256r1, brainpoolP384r1 defined in .

Applicable Specifications for the use of PQC Algorithms in OpenPGP This document is to be understood as an extension of , which introduced PQC in OpenPGP, in that it defines further algorithm code points. All general specifications in that pertain to the ML-KEM and ML-DSA composite schemes or generally cryptographic schemes defined therein equally apply to the schemes specified in this document.

Preliminaries This section provides some preliminaries for the definitions in the subsequent sections.

Elliptic curves

SEC1 EC Point Wire Format Elliptic curve points of the generic prime curves are encoded using the SEC1 (uncompressed) format as the following octet string: where X and Y are coordinates of the elliptic curve point P = (X, Y), and each coordinate is encoded in the big-endian format and zero-padded to the adjusted underlying field size. The adjusted underlying field size is the underlying field size rounded up to the nearest 8-bit boundary, as noted in the "Field size" column in , , or . This encoding is compatible with the definition given in .

Measures to Ensure Secure Implementations In the following measures are described that ensure secure implementations according to existing best practices and standards defining the operations of Elliptic Curve Cryptography. Even though the zero point, also called the point at infinity, may occur as a result of arithmetic operations on points of an elliptic curve, it MUST NOT appear in any ECC data structure defined in this document. Furthermore, when performing the explicitly listed operations in it is REQUIRED to follow the specification and security advisory mandated from the respective elliptic curve specification.

Supported Public Key Algorithms This section specifies the composite ML-KEM+ECDH and ML-DSA+ECDSA schemes. All of these schemes are fully specified via their algorithm ID, i.e., they are not parametrized.

Algorithm Specifications For encryption, the following composite KEM schemes are specified: KEM algorithm specifications

ID	Algorithm	Requirement	Definition
TBD	ML-KEM-512+ECDH-NIST-P-256	MAY
TBD	ML-KEM-768+ECDH-NIST-P-384	MAY
TBD	ML-KEM-1024+ECDH-NIST-P-384	MAY
TBD	ML-KEM-768+ECDH-brainpoolP256r1	MAY
TBD	ML-KEM-1024+ECDH-brainpoolP384r1	MAY

For signatures, the following (composite) signature schemes are specified: Signature algorithm specifications

ID	Algorithm	Requirement	Definition
TBD	ML-DSA-44+ECDSA-NIST-P-256	MAY
TBD	ML-DSA-65+ECDSA-NIST-P-384	MAY
TBD	ML-DSA-87+ECDSA-NIST-P-384	MAY
TBD	ML-DSA-65+ECDSA-brainpoolP256r1	MAY
TBD	ML-DSA-87+ECDSA-brainpoolP384r1	MAY

Experimental Codepoints for Interop Testing [ Note: this section to be removed before publication ] Algorithms indicated as MAY are not assigned a codepoint in the current state of the draft since there are not enough private/experimental code points available to cover all newly introduced public-key algorithm identifiers. The use of private/experimental codepoints during development are intended to be used in non-released software only, for experimentation and interop testing purposes only. An OpenPGP implementation MUST NOT produce a formal release using these experimental codepoints. This draft will not be sent to IANA without every listed algorithm having a non-experimental codepoint.

Algorithm Combinations

Composite KEMs The ML-KEM+ECDH public-key encryption involves both the ML-KEM and an ECC-based KEM in an a priori non-separable manner. This is achieved via KEM combination, i.e. both key encapsulations/decapsulations are performed in parallel, and the resulting key shares are fed into a key combiner to produce a single shared secret for message encryption.

Composite Signatures The ML-DSA+ECDSA signature consists of independent ML-DSA and ECC signatures, and an implementation MUST successfully validate both signatures to state that the ML-DSA+ECDSA signature is valid.

Composite KEM schemes

Building Blocks

ECC-Based KEMs In this section we define the encryption, decryption, and data formats for the ECDH component of the composite algorithms. and describe the ECDH-KEM parameters and artifact lengths. NIST curves parameters and artifact lengths

	NIST P-256	NIST P-384
Algorithm ID reference	TBD (ML-KEM-512+ECDH-NIST-P-256)	TBD (ML-KEM-768+ECDH-NIST-P-384, ML-KEM-1024+ECDH-NIST-P-384, )
Field size	32 octets	48 octets
ECDH public key	65 octets of SEC1-encoded public point	97 octets of SEC1-encoded public point
ECDH secret key	32 octets big-endian encoded secret scalar	48 octets big-endian encoded secret scalar
ECDH ephemeral	65 octets of SEC1-encoded ephemeral point	97 octets of SEC1-encoded ephemeral point
ECDH share	65 octets of SEC1-encoded shared point	97 octets of SEC1-encoded shared point
Key share	32 octets	64 octets
Hash	SHA3-256	SHA3-512

Brainpool curves parameters and artifact lengths

	brainpoolP256r1	brainpoolP384r1
Algorithm ID reference	TBD (ML-KEM-768+ECDH-brainpoolP256r1)	TBD (ML-KEM-1024+ECDH-brainpoolP384r1)
Field size	32 octets	48 octets
ECDH public key	65 octets of SEC1-encoded public point	97 octets of SEC1-encoded public point
ECDH secret key	32 octets big-endian encoded secret scalar	48 octets big-endian encoded secret scalar
ECDH ephemeral	65 octets of SEC1-encoded ephemeral point	97 octets of SEC1-encoded ephemeral point
ECDH share	65 octets of SEC1-encoded shared point	97 octets of SEC1-encoded shared point
Key share	32 octets	64 octets
Hash	SHA3-256	SHA3-512

The SEC1 format for point encoding is defined in . The various procedures to perform the operations of an ECC-based KEM are defined in the following subsections. Specifically, each of these subsections defines the instances of the following operations: and To instantiate ECDH-KEM, one must select a parameter set from or .

ECDH-KEM The operation ECDH-KEM.Encaps() is defined as follows: 1. Generate an ephemeral key pair {v, V=vG} as defined in or where v is a random scalar with 0 < v < n, n being the base point order of the elliptic curve domain parameters

1. Compute the shared point S = vR, where R is the component public key ecdhPublicKey, according to or
2. Extract the X coordinate from the SEC1 encoded point S = 04 || X || Y as defined in section
3. Set the output ecdhCipherText to the SEC1 encoding of V
4. Set the output ecdhKeyShare to Hash(X || ecdhCipherText || ecdhPublicKey), with Hash chosen according to or

The operation ECDH-KEM.Decaps() is defined as follows:

1. Compute the shared Point S as rV, where r is the ecdhSecretKey and V is the ecdhCipherText, according to or
2. Extract the X coordinate from the SEC1 encoded point S = 04 || X || Y as defined in section
3. Set the output ecdhKeyShare to Hash(X || ecdhCipherText || ecdhPublicKey), with Hash chosen according to or

ML-KEM ML-KEM features the following operations: and The above are the operations ML-KEM.Encaps and ML-KEM.Decaps defined in . Note that mlkemPublicKey is the encapsulation and mlkemSecretKey is the decapsulation key. ML-KEM has the parametrization with the corresponding artifact lengths in octets as given in . All artifacts are encoded as defined in . ML-KEM parameters artifact lengths in octets

Algorithm ID reference	ML-KEM	Public key	Secret key	Ciphertext	Key share
TBD	ML-KEM-512	800	1632	768	32
TBD	ML-KEM-768	1184	2400	1088	32
TBD	ML-KEM-1024	1568	3168	1568	32

To instantiate ML-KEM, one must select a parameter set from the column "ML-KEM" of . The procedure to perform ML-KEM.Encaps() is as follows:

1. Invoke (mlkemCipherText, mlkemKeyShare) <- ML-KEM.Encaps(mlkemPublicKey), where mlkemPublicKey is the recipient's public key
2. Set mlkemCipherText as the ML-KEM ciphertext
3. Set mlkemKeyShare as the ML-KEM symmetric key share

The procedure to perform ML-KEM.Decaps() is as follows:

1. Invoke mlkemKeyShare <- ML-KEM.Decaps(mlkemCipherText, mlkemSecretKey)
2. Set mlkemKeyShare as the ML-KEM symmetric key share

Composite Encryption Schemes with ML-KEM specifies the following ML-KEM+ECDH-KEM composite public-key encryption schemes: ML-KEM+ECDH composite schemes

Algorithm ID reference	ML-KEM	ECDH-KEM curve
TBD (ML-KEM-512+ECDH-NIST-P-256)	ML-KEM-512	NIST P-256
TBD (ML-KEM-768+ECDH-NIST-P-384)	ML-KEM-768	NIST P-384
TBD (ML-KEM-1024+ECDH-NIST-P-384)	ML-KEM-1024	NIST P-384
TBD (ML-KEM-768+ECDH-brainpoolP256r1)	ML-KEM-768	brainpoolP256r1
TBD (ML-KEM-1024+ECDH-brainpoolP384r1)	ML-KEM-1024	brainpoolP384r1

The ML-KEM+ECDH composite public-key encryption schemes are built according to the following principal design:

• The ML-KEM encapsulation algorithm is invoked to create an ML-KEM ciphertext together with an ML-KEM symmetric key share.
• The encapsulation algorithm of an ECDH-KEM is invoked to create an ECC ciphertext together with an ECC symmetric key share.
• A Key-Encryption-Key (KEK) is computed as the output of a key combiner that receives as input both of the above created symmetric key shares and the protocol binding information.
• The session key for content encryption is then encrypted with the AES Key Wrap Algorithm with AES-256 as the encryption algorithm and using the KEK as the encryption key.
• The PKESK package's algorithm-specific parts are made up of the ML-KEM ciphertext, the ECC ciphertext, and the wrapped session key.

Key combiner For the composite KEM schemes defined in this document the procedure multiKeyCombine that is defined in Section 4.2.1 MUST be used to compute the KEK that wraps a session key.

Key generation procedure The implementation MUST independently generate the ML-KEM and the ECC component keys. ML-KEM key generation follows the specification and the artifacts are encoded as fixed-length octet strings as defined in . For ECC this is done following the relative specification in or , and encoding the outputs as fixed-length octet strings in the format specified in or .

Encryption procedure The procedure to perform public-key encryption with an ML-KEM+ECDH composite scheme is as follows:

1. Take the recipient's authenticated public-key packet pkComposite and sessionKey as input
2. Parse the algorithm ID from pkComposite
3. Extract the ecdhPublicKey and mlkemPublicKey component from the algorithm specific data encoded in pkComposite with the format specified in .
4. Instantiate the ECDH-KEM and the ML-KEM depending on the algorithm ID according to
5. Compute (ecdhCipherText, ecdhKeyShare) := ECDH-KEM.Encaps(ecdhPublicKey)
6. Compute (mlkemCipherText, mlkemKeyShare) := ML-KEM.Encaps(mlkemPublicKey)
7. Compute KEK = multiKeyCombine(mlkemKeyShare, mlkemCipherText, mlkemPublicKey, eccKeyShare, eccCipherText, eccPublicKey, algId)
8. Compute C := AESKeyWrap(KEK, sessionKey) with AES-256 as per that includes a 64 bit integrity check
9. Output the algorithm specific part of the PKESK as eccCipherText || mlkemCipherText len(symAlgId, C) (|| symAlgId) || C, where both symAlgId and len(C, symAlgId) are single octet fields, symAlgId denotes the symmetric algorithm ID used and is present only for a v3 PKESK, and len(C, symAlgId) denotes the combined octet length of the fields specified as the arguments.

Decryption procedure The procedure to perform public-key decryption with an ML-KEM+ECDH composite scheme is as follows:

1. Take the matching PKESK and own secret key packet as input
2. From the PKESK extract the algorithm ID and the encryptedKey, i.e., the wrapped session key
3. Check that the own and the extracted algorithm ID match
4. Parse the ecdhSecretKey and mlkemSecretKey from the algorithm specific data of the own secret key encoded in the format specified in
5. Instantiate the ECDH-KEM and the ML-KEM depending on the algorithm ID according to
6. Parse ecdhCipherText, mlkemCipherText, and C from encryptedKey encoded as ecdhCipherText || mlkemCipherText || len(symAlgId, C) (|| symAlgId) || C as specified in , where symAlgId is present only in the case of a v3 PKESK.
7. Compute (ecdhKeyShare) := ECDH-KEM.Decaps(ecdhCipherText, ecdhSecretKey, ecdhPublicKey)
8. Compute (mlkemKeyShare) := ML-KEM.Decaps(mlkemCipherText, mlkemSecretKey)
9. Compute KEK = multiKeyCombine(mlkemKeyShare, mlkemCipherText, mlkemPublicKey, eccKeyShare, eccCipherText, eccPublicKey, algId)
10. Compute sessionKey := AESKeyUnwrap(KEK, C) with AES-256 as per , aborting if the 64 bit integrity check fails
11. Output sessionKey

Packet specifications

Public-Key Encrypted Session Key Packets (Tag 1) The algorithm-specific fields consists of the output of the encryption procedure described in :

• A fixed-length octet string representing an ECC ephemeral public key in the format associated with the curve as specified in .
• A fixed-length octet string of the ML-KEM ciphertext, whose length depends on the algorithm ID as specified in .
• A one-octet size of the following fields.
• Only in the case of a v3 PKESK packet: a one-octet symmetric algorithm identifier.
• The wrapped session key represented as an octet string.

Note that like in the case of the algorithms X25519 and X448 specified in , for the ML-KEM+ECDH composite schemes, in the case of a v3 PKESK packet, the symmetric algorithm identifier is not encrypted. Instead, it is placed in plaintext after the mlkemCipherText and before the length octet preceding the wrapped session key. In the case of v3 PKESK packets for ML-KEM composite schemes, the symmetric algorithm used MUST be AES-128, AES-192 or AES-256 (algorithm ID 7, 8 or 9). In the case of a v3 PKESK, a receiving implementation MUST check if the length of the unwrapped symmetric key matches the symmetric algorithm identifier, and abort if this is not the case.

Key Material Packets The algorithm-specific public key is this series of values:

• A fixed-length octet string representing an EC point public key, in the point format associated with the curve specified in .
• A fixed-length octet string containing the ML-KEM public key, whose length depends on the algorithm ID as specified in .

The algorithm-specific secret key is these two values:

• A fixed-length octet string of the encoded secret scalar, whose encoding and length depend on the algorithm ID as specified in .
• A fixed-length octet string containing the ML-KEM secret key, whose length depends on the algorithm ID as specified in .

Composite Signature Schemes

Building blocks

ECDSA-Based signatures To sign and verify with ECDSA the following operations are defined: and Here, the operation ECDSA.Sign() is defined as the algorithm in Section "6.4.1 ECDSA Signature Generation Algorithm" of , however, excluding Step 1: H = Hash(M) in that algorithm specification, as in this specification the message digest H is a direct input to the operation ECDSA.Sign(). Equivalently, the operation ECDSA.Sign() can be understood as representing the algorithm under Section "4.2.1.1. Signature Algorithm" in , again with the difference that in this specification the message digest H_Tau(M) appearing in Step 5 of the algorithm specification is the direct input to the operation ECDSA.Sign() and thus the hash computation is not carried out. The same statement holds for the definition of the verification operation ECDSA.Verify(): it is given either through the algorithm defined in Section "6.4.2 ECDSA Signature Verification Algorithm" of omitting the message digest computation in Step 2 or by the algorithm in Section "4.2.1.2. Verification Algorithm" of omitting the message digest computation in Step 3. The public keys MUST be encoded in SEC1 format as defined in section . The secret key, as well as both values R and S of the signature MUST each be encoded as a big-endian integer in a fixed-length octet string of the specified size. The following table describes the ECDSA parameters and artifact lengths: ECDSA parameters and artifact lengths in octets

Algorithm ID reference	Curve	Field size	Public key	Secret key	Signature value R	Signature value S
TBD (ML-DSA-44+ECDSA-NIST-P-256)	NIST P-256	32	65	32	32	32
TBD (ML-DSA-65+ECDSA-NIST-P-384,ML-DSA-87+ECDSA-NIST-P-384)	NIST P-384	48	97	48	48	48
TBD (ML-DSA-65+ECDSA-brainpoolP256r1)	brainpoolP256r1	32	65	32	32	32
TBD (ML-DSA-87+ECDSA-brainpoolP384r1)	brainpoolP384r1	48	97	48	48	48

ML-DSA signatures For ML-DSA signature generation the default hedged version of ML-DSA.Sign given in is used. That is, to sign with ML-DSA the following operation is defined: For ML-DSA signature verification the algorithm ML-DSA.Verify given in is used. That is, to verify with ML-DSA the following operation is defined: ML-DSA has the parametrization with the corresponding artifact lengths in octets as given in . All artifacts are encoded as defined in . ML-DSA parameters and artifact lengths in octets

Algorithm ID reference	ML-DSA	Public key	Secret key	Signature value
TBD	ML-DSA-44	1312	2528	2420
TBD	ML-DSA-65	1952	4032	3293
TBD	ML-DSA-87	2592	4896	4595

Composite Signature Schemes with ML-DSA

Signature data digest Signature data (i.e. the data to be signed) is digested prior to signing operations, see , Section 5.2.4. Composite ML-DSA+ECDSA signatures MUST use the associated hash algorithm as specified in for the signature data digest. Signatures using other hash algorithms MUST be considered invalid. An implementation supporting a specific ML-DSA+ECDSA algorithm MUST also support the matching hash algorithm. Binding between ML-DSA+ECDSA and signature data digest

Algorithm ID reference	Hash function	Hash function ID reference
TBD (ML-DSA-44 IDs)	SHA3-256	12
TBD (ML-DSA-65 IDs)	SHA3-512	14
TBD (ML-DSA-87 IDs)	SHA3-512	14

Key generation procedure The implementation MUST independently generate the ML-DSA and the ECC component keys. ML-DSA key generation follows the specification and the artifacts are encoded as fixed-length octet strings as defined in . For ECC this is done following the relative specification in or , and encoding the artifacts as specified in as fixed-length octet strings.

Signature Generation To sign a message M with ML-DSA+ECDSA the following sequence of operations has to be performed:

1. Generate dataDigest according to , Section 5.2.4
2. Create the ECDSA signature over dataDigest with ECDSA.Sign() from
3. Create the ML-DSA signature over dataDigest with ML-DSA.Sign() from
4. Encode the ECDSA and ML-DSA signatures according to the packet structure given in .

Signature Verification To verify an ML-DSA+ECDSA signature the following sequence of operations has to be performed:

1. Verify the ECDSA signature with ECDSA.Verify() from
2. Verify the ML-DSA signature with ML-DSA.Verify() from

As specified in an implementation MUST validate both signatures, i.e. ECDSA and ML-DSA, successfully to state that a composite ML-DSA+ECDSA signature is valid.

Packet Specifications

Signature Packet (Tag 2) The composite ML-DSA+ECDSA schemes MUST be used only with v6 signatures, as defined in . The algorithm-specific v6 signature parameters for ML-DSA+ECDSA signatures consist of:

• A fixed-length octet string of the big-endian encoded ECDSA value R, whose length depends on the algorithm ID as specified in .
• A fixed-length octet string of the big-endian encoded ECDSA value S, whose length depends on the algorithm ID as specified in .
• A fixed-length octet string of the ML-DSA signature value, whose length depends on the algorithm ID as specified in .

Key Material Packets The composite ML-DSA+ECDSA schemes MUST be used only with v6 keys, as defined in . The algorithm-specific public key for ML-DSA+ECDSA keys is this series of values:

• A fixed-length octet string representing the ECDSA public key in SEC1 format, as specified in section and with length specified in .
• A fixed-length octet string containing the ML-DSA public key, whose length depends on the algorithm ID as specified in .

The algorithm-specific secret key for ML-DSA+ECDSA keys is this series of values:

• A fixed-length octet string representing the ECDSA secret key as a big-endian encoded integer, whose length depends on the algorithm used as specified in .
• A fixed-length octet string containing the ML-DSA secret key, whose length depends on the algorithm ID as specified in .

Security Considerations TBD

IANA Considerations IANA is requested to add the algorithm IDs defined in to the existing registry OpenPGP Public Key Algorithms. The field specifications enclosed in brackets for the ML-KEM+ECDH composite algorithms denote fields that are only conditionally contained in the data structure. [Note: Once the working group has agreed on the actual algorithm choice, the following table with the requested IANA updates will be filled out.] IANA updates for registry 'OpenPGP Public Key Algorithms'

ID	Algorithm	Public Key Format	Secret Key Format	Signature Format	PKESK Format	Reference
TBD	ML-DSA-65+TBD	TBD octets TBD public key , TBD octets ML-DSA-65 public key ()	TBD octets TBD secret key , TBD octets ML-DSA-65 secret ()	TBD octets TBD signature , TBD octets ML-DSA-65 signature ()	N/A

Changelog

Contributors Stavros Kousidis

References Normative References This memo specifies two elliptic curves over prime fields that offer a high level of practical security in cryptographic applications, including Transport Layer Security (TLS). These curves are intended to operate at the ~128-bit and ~224-bit security level, respectively, and are generated deterministically based on a list of required properties. This document describes elliptic curve signature scheme Edwards-curve Digital Signature Algorithm (EdDSA). The algorithm is instantiated with recommended parameters for the edwards25519 and edwards448 curves. An example implementation and test vectors are provided. Many protocols make use of points of extensibility that use constants to identify various protocol parameters. To ensure that the values in these fields do not have conflicting uses and to promote interoperability, their allocations are often coordinated by a central record keeper. For IETF protocols, that role is filled by the Internet Assigned Numbers Authority (IANA). To make assignments in a given registry prudently, guidance describing the conditions under which new values should be assigned, as well as when and how modifications to existing values can be made, is needed. This document defines a framework for the documentation of these guidelines by specification authors, in order to assure that the provided guidance for the IANA Considerations is clear and addresses the various issues that are likely in the operation of a registry. This is the third edition of this document; it obsoletes RFC 5226. Aiven Proton AG Sequoia-PGP FSIJ This document specifies the message formats used in OpenPGP. OpenPGP provides encryption with public-key or symmetric cryptographic algorithms, digital signatures, compression and key management. This document is maintained in order to publish all necessary information needed to develop interoperable applications based on the OpenPGP format. It is not a step-by-step cookbook for writing an application. It describes only the format and methods needed to read, check, generate, and write conforming packets crossing any network. It does not deal with storage and implementation questions. It does, however, discuss implementation issues necessary to avoid security flaws. This document obsoletes: RFC 4880 (OpenPGP), RFC 5581 (Camellia in OpenPGP) and RFC 6637 (Elliptic Curves in OpenPGP). Informative References This memo proposes several elliptic curve domain parameters over finite prime fields for use in cryptographic applications. The domain parameters are consistent with the relevant international standards, and can be used in X.509 certificates and certificate revocation lists (CRLs), for Internet Key Exchange (IKE), Transport Layer Security (TLS), XML signatures, and all applications or protocols based on the cryptographic message syntax (CMS). This document is not an Internet Standards Track specification; it is published for informational purposes. Information Technology Laboratory, National Institute of Standards and Technology Standards for Efficient Cryptography Group National Institute of Standards and Technology National Institute of Standards and Technology National Institute of Standards and Technology Federal Office for Information Security, Germany

Test Vectors TBD

Sample v6 PQC Subkey Artifacts TBD ## V4 PQC Subkey Artifacts TBD

Acknowledgments