Internet-Draft ACVP ML-KEM April 2024
Celi Expires 1 November 2024 [Page]
Workgroup:
Network Working Group
Internet-Draft:
draft-celi-acvp-ml-kem-01
:
Published:
Intended Status:
Informational
Expires:
Author:
C. Celi, Ed.

ACVP ML-KEM JSON Specification

Status of This Memo

This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79.

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This Internet-Draft will expire on 1 November 2024.

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Table of Contents

1. Acknowledgements

There are no acknowledgements.

2. Abstract

This document defines the JSON schema for testing Module Lattice-based Key Encapsulation Mechanism (ML-KEM) implementations with the ACVP specification.

3. Introduction

The Automated Crypto Validation Protocol (ACVP) defines a mechanism to automatically verify the cryptographic implementation of a software or hardware crypto module. The ACVP specification defines how a crypto module communicates with an ACVP server, including crypto capabilities negotiation, session management, authentication, vector processing and more. The ACVP specification does not define algorithm specific JSON constructs for performing the crypto validation. A series of ACVP sub-specifications define the constructs for testing individual crypto algorithms. Each sub-specification addresses a specific class of crypto algorithms. This sub-specification defines the JSON constructs for testing Module Lattice-based Key Encapsulation Mechanism (ML-KEM) implementations using ACVP.

4. Conventions

4.1. Notation conventions

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 of [RFC2119] and [RFC8174] when, and only when, they appear in all capitals, as shown here.

4.2. Terms and Definitions

4.2.1. Prompt

JSON sent from the server to the client describing the tests the client performs

4.2.2. Registration

The initial request from the client to the server describing the capabilities of one or several algorithm, mode and revision combinations

4.2.3. Response

JSON sent from the client to the server in response to the prompt

4.2.4. Test Case

An individual unit of work within a prompt or response

4.2.5. Test Group

A collection of test cases that share similar properties within a prompt or response

4.2.6. Test Vector Set

A collection of test groups under a specific algorithm, mode, and revision

4.2.7. Validation

JSON sent from the server to the client that specifies the correctness of the response

5. Supported ML-KEM Algorithms

The following ML-KEM algorithms MAY be advertised by the ACVP compliant cryptographic module. The list is in the form "algorithm / mode / revision".

6. Test Types and Test Coverage

6.1. Test Types

The ACVP server performs a set of tests on the specified ML-KEM algorithm in order to assess the correctness and robustness of the implementation. A typical ACVP validation session SHALL require multiple tests to be performed for every supported permutation of ML-KEM capabilities. This section describes the design of the tests used to validate implementations of the ML-KEM algorithms.

  • ML-KEM / keyGen / * "AFT" - Algorithm Functional Test. The IUT is REQUIRED for each test case provided, to generate a key pair from a provided seed. The key pair is communicated to the ACVP server and validated.
  • ML-KEM / encapDecap / * "AFT" - Algorithm Functional Test. The server will generate a random m and encapsulation key ek. The IUT SHALL generate the corresponding shared secret k and ciphertext c.
  • ML-KEM /encapDecap / * "VAL" - Validation Test. The server will generate a decapsulation key dk and a potentially valid or invalid ciphertext c. The IUT SHALL generate the corresponding shared secret k whether the k is provided from the valid decapsulation route or from the implicit rejection present in [FIPS203] Algorithm 17.

6.2. Test Coverage

The tests described in this document have the intention of ensuring an implementation is conformant to [FIPS203].

6.2.1. Requirements Covered

  • The tests will ensure conformity and correctness of an implementation of the algorithms supported.

6.2.2. Requirements Not Covered

  • FIPS 203 Section 3.3. Requirements for ML-KEM Implementations. Requirements outlined in this section are not testable by an ACVP server. An ACVP server will not test the zeroization of intermediate values, security strength of the deterministic random bit generators (DRBGs), or incorrect length signatures or public keys.

7. Capabilities Registration

ACVP requires crypto modules to register their capabilities. This allows the crypto module to advertise support for specific algorithms, notifying the ACVP server which algorithms need test vectors generated for the validation process. This section describes the constructs for advertising support of ML-KEM algorithms to the ACVP server.

The algorithm capabilities MUST be advertised as JSON objects within the 'algorithms' value of the ACVP registration message. The 'algorithms' value is an array, where each array element is an individual JSON object defined in this section. The 'algorithms' value is part of the 'capability_exchange' element of the ACVP JSON registration message. See the ACVP specification [ACVP] for more details on the registration message.

7.1. Prerequisites

Each algorithm implementation MAY rely on other cryptographic primitives. For example, RSA Signature algorithms depend on an underlying hash function. Each of these underlying algorithm primitives must be validated, either separately or as part of the same submission. ACVP provides a mechanism for specifying the required prerequisites:

Prerequisites, if applicable, MUST be submitted in the registration as the prereqVals JSON property array inside each element of the algorithms array. Each element in the prereqVals array MUST contain the following properties

Table 1: Prerequisite Properties
JSON Property Description JSON Type
algorithm a prerequisite algorithm string
valValue algorithm validation number string

A "valValue" of "same" SHALL be used to indicate that the prerequisite is being met by a different algorithm in the capability exchange in the same registration.

An example description of prerequisites within a single algorithm capability exchange looks like this

"prereqVals":
[
  {
    "algorithm": "Alg1",
    "valValue": "Val-1234"
  },
  {
    "algorithm": "Alg2",
    "valValue": "same"
  }
]

7.2. Required Prerequisite Algorithms for ML-KEM Validations

Each ML-KEM implementation relies on other cryptographic primitives. For example, ML-KEM keyGen uses an underlying SHA algorithm. Each of these underlying algorithm primitives must be validated, either separately or as part of the same submission. ACVP provides a mechanism for specifying the required prerequisites:

Table 2: Required ML-KEM Prerequisite Algorithms JSON Values
JSON Value Description JSON Type Valid Values
algorithm a prerequisite algorithm string SHA, or DRBG
valValue algorithm validation number string Actual number or "same"
prereqAlgVal prerequisite algorithm validation object with algorithm and valValue properties See above

7.3. ML-KEM Algorithm Registration Properties

Each ML-KEM algorithm capability advertised is a self-contained JSON object using the following values.

Table 3: ML-KEM Algorithm Capabilities JSON Values
JSON Value Description JSON Type Valid Values
algorithm The ML-KEM algorithm to be validated string See Section 5
mode The ML-KEM mode to be validated string See Section 5
revision The algorithm testing revision to use string See Section 5
prereqVals Prerequisite algorithm validations array of prereqAlgVal objects See Section 7.2
parameterSets The ML-KEM parameter sets supported array of strings "ML-KEM-512", "ML-KEM-768", "ML-KEM-1024"
functions The ML-KEM encapsulation or decapsulation modes supported array of strings "encapsulation", "decapsulation"

Note: The functions property is only applicable to ML-KEM / encapDecap / FIPS203.

7.3.1. ML-KEM keyGen Mode Capabilities Example

Below is an example of the registration for ML-KEM / keyGen / FIPS203

{
    "algorithm": "ML-KEM",
    "mode": "keyGen",
    "revision": "FIPS203",
    "prereqVals": [
        {
            "algorithm": "SHA",
            "valValue": "123456"
        }
    ],
    "parameterSets": ["ML-KEM-512", "ML-KEM-768", "ML-KEM-1024"]
}

7.3.2. ML-KEM encapDecap Mode Capabilities Example

Below is an example of the registration for ML-KEM / encapDecap / FIPS203

{
    "algorithm": "ML-KEM",
    "mode": "encapDecap",
    "revision": "FIPS203",
    "prereqVals": [
        {
            "algorithm": "SHA",
            "valValue": "123456"
        }
    ],
    "parameterSets": ["ML-KEM-512", "ML-KEM-768", "ML-KEM-1024"]
    "functions": ["encapsulation", "decapsulation"]
}

8. Test Vectors

The ACVP server provides test vectors to the ACVP client, which are then processed and returned to the ACVP server for validation. A typical ACVP validation test session would require multiple test vector sets to be downloaded and processed by the ACVP client. Each test vector set represents an individual algorithm defined during the capability exchange. This section describes the JSON schema for a test vector set used with Module Lattice-based Key Encapsulation Mechanism (ML-KEM) algorithms.

The test vector set JSON schema is a multi-level hierarchy that contains meta data for the entire vector set as well as individual test vectors to be processed by the ACVP client. The following table describes the JSON elements at the top level of the hierarchy.

Table 4: Top Level Test Vector JSON Elements
JSON Values Description JSON Type
acvVersion Protocol version identifier string
vsId Unique numeric vector set identifier integer
algorithm Algorithm defined in the capability exchange string
mode Mode defined in the capability exchange string
revision Protocol test revision selected string
testGroups Array of test groups containing test data, see Section 8, Paragraph 6 array

An example of this would look like this

[
  {
    "acvVersion": <version>
  },
  {
    "vsId": 1,
    "algorithm": "Alg1",
    "mode": "Mode1",
    "revision": "Revision1.0",
    "testGroups": [ ... ]
  }
]

==

8.1. ML-KEM keyGen Test Vectors

8.1.1. ML-KEM keyGen Test Groups JSON Schema

The testGroups element at the top level in the test vector JSON object is an array of test groups. Test vectors are grouped into similar test cases to reduce the amount of data transmitted in the vector set. For instance, all test vectors that use the same key size would be grouped together. The Test Group JSON object contains meta data that applies to all test vectors within the group. The following table describes the secure hash JSON elements of the Test Group JSON object.

The test group for ML-KEM / keyGen / FIPS203 is as follows:

Table 5: ML-KEM keyGen Test Group JSON Object
JSON Value Description JSON type
testType The test operation performed string
parameterSet The ML-KEM parameter set used string
tests Array of individual test vector JSON objects, which are defined in Section 8.1.2 array

8.1.2. ML-KEM keyGen Test Case JSON Schema

Each test group contains an array of one or more test cases. Each test case is a JSON object that represents a single test vector to be processed by the ACVP client. The following table describes the JSON elements for each ML-KEM test vector.

Table 6: ML-KEM keyGen Test Case JSON Object
JSON Value Description JSON type
tcId Numeric identifier for the test case, unique across the entire vector set integer
d The seed d used to generate the key pair hex
z The seed z used to generate the key pair hex

The following is an example JSON object sent from the server to the client for ML-KEM / keyGen / FIPS203.

[
    {
        "acvVersion": <acvp-version>
    },
    {
        "vsId": 1564,
        "algorithm": "ML-KEM",
        "mode": "keyGen",
        "revision": "FIPS203",
        "testGroups": [
            {
                "tgId": 1,
                "testType": "AFT",
                "parameterSet": "ML-KEM-512",
                "tests": [
                    {
                        "tcId": 1,
                        "d": "C105DC2...",
                        "z": "AD310AB..."
                    }
                ]
            }
        ]
    }
]

8.2. ML-KEM encapDecap Test Vectors

8.2.1. ML-KEM encapDecap Test Groups JSON Schema

The testGroups element at the top level in the test vector JSON object is an array of test groups. Test vectors are grouped into similar test cases to reduce the amount of data transmitted in the vector set. For instance, all test vectors that use the same key size would be grouped together. The Test Group JSON object contains meta data that applies to all test vectors within the group. The following table describes the secure hash JSON elements of the Test Group JSON object.

The test group for ML-KEM / encapDecap / FIPS203 is as follows:

Table 7: ML-KEM encapDecap Test Group JSON Object
JSON Value Description JSON type
testType The test operation performed string
parameterSet The ML-KEM parameter set used string
function Whether the tests are running encapsulation or decapsulation string
dk The decapsulation key when "testType": "VAL" hex
tests Array of individual test vector JSON objects, which are defined in Section 8.2.2 array

8.2.2. ML-KEM encapDecap Test Groups JSON Schema

Each test group contains an array of one or more test cases. Each test case is a JSON object that represents a single test vector to be processed by the ACVP client. The following table describes the JSON elements for each ML-KEM test vector.

Table 8: ML-KEM encapDecap Test Case JSON Object
JSON Value Description JSON type
tcId Numeric identifier for the test case, unique across the entire vector set integer
ek The encapsulation key when "testType": "AFT" hex
m The random value used to derive the shared key when "testType": "AFT" hex
c The cipher text when "testType": "VAL" hex

The following is an example JSON object sent from the server to the client for ML-KEM / encapDecap / FIPS203.

[
    {
        "acvVersion": <acvp-version>
    },
    {
        "vsId": 0,
        "algorithm": "ML-KEM",
        "mode": "encapDecap",
        "revision": "FIPS203",
        "testGroups": [
            {
                "tgId": 1,
                "testType": "AFT",
                "parameterSet": "ML-KEM-512",
                "function": "encapsulation",
                "tests": [
                    {
                        "tcId": 1,
                        "ek": "75A72D...",
                        "m": "013FD9A..."
                    },
                ]
            },
            {
                "tgId": 2,
                "testType": "VAL",
                "parameterSet": "ML-KEM-512",
                "function": "decapsulation",
                "dk": "DF479939FAA...",
                "tests": [
                    {
                        "tcId": 76,
                        "c": "49D873A9..."
                    }
                ]
            }
        ]
    }
]

9. Test Vector Responses

After the ACVP client downloads and processes a vector set, it must send the response vectors back to the ACVP server. The following table describes the JSON object that represents a vector set response.

Table 9: Response JSON Object
JSON Property Description JSON Type
acvVersion The ACVP version used string
vsId The vector set identifier integer
testGroups The test group objects in the response, see Table 10 array

An example of this is the following

{
    "acvVersion": "version",
    "vsId": 1,
    "testGroups": [ ... ]
}

The 'testGroups' section is used to organize the ACVP client response in a similar manner to how it distributes vectors.

Table 10: Response Group Objects
JSON Property Description JSON Type
tgId The test group identifier integer
tests The test case objects in the response, depending on the algorithm see Table 11 or Table 13 array

An example of this is the following

{
    "tgId": 1,
    "tests": [ ... ]
}

9.1. ML-KEM keyGen Test Vector Responses

Each test group contains an array of one or more test cases. Each test case is a JSON object that represents a single test vector to be processed by the ACVP client. The following table describes the JSON elements for each ML-KEM / keyGen / FIPS203 test vector.

Table 11: ML-KEM keyGen Test Case Response JSON Object
JSON Value Description JSON type
tcId The test case identifier integer
ek The computed encapsulation key hex
dk The computed decapsulation key hex

The following is an example JSON test vector response object for ML-KEM / keyGen / FIPS203.

[
    {
        "acvVersion": <acvp-version>
    },
    {
        "vsId": 0,
        "testGroups": [
            {
                "tgId": 1,
                "tests": [
                    {
                        "tcId": 1,
                        "ek": "238B9517653...",
                        "dk": "0A851B79883..."
                    }
                ]
            }
        ]
    }
]

9.2. ML-KEM encapDecap Test Vector Responses

The test groups for ML-KEM / encapDecap / FIPS203 contain public key properties. The groups can be described using the following table.

Table 12: ML-KEM encapDecap Test Group Response JSON Object
JSON Value Description JSON type
tgId The test group identifier integer
tests The individual test cases for the group array

Each test group contains an array of one or more test cases. Each test case is a JSON object that represents a single test vector to be processed by the ACVP client. The following table describes the JSON elements for each ML-KEM / encapDecap / FIPS203 test vector.

Table 13: ML-KEM encapDecap Test Case Response JSON Object
JSON Value Description JSON type
tcId The test case identifier integer
c The generated ciphertext only for "testType": "AFT" hex
k The generated shared secret hex

The following is an example JSON test vector response object for ML-KEM / encapDecap / FIPS203.

[
    {
        "acvVersion": <acvp-version>
    },
    {
        "vsId": 1564,
        "testGroups": [
            {
                "tgId": 1,
                "tests": [
                    {
                        "tcId": 1,
                        "c": "7DFC404E2...",
                        "k": "5C82A1AB3..."
                    }
                ]
            },
            {
                "tgId": 2,
                "tests": [
                    {
                        "tcId": 76,
                        "k": "87B9103AA..."
                    }
                ]
            }
        ]
    }
]

10. Security Considerations

There are no additional security considerations outside of those outlined in the ACVP document.

11. IANA Considerations

This document does not require any action by IANA.

12. Normative References

[RFC2119]
Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
[RFC8174]
Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", RFC 8174, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
[FIPS203]
"", NIST FIPS 203.
[ACVP]
Fussell, B., Vassilev, A., and H. Booth, "Automatic Cryptographic Validation Protocol", ACVP, .

Author's Address

Christopher Celi (editor)