| 1. Definition | 2. Functional Requirements | 3. Syntax | 4. Semantics |
1 Definition
The Security Algorithm Taxonomy defines the set of identifiers used by MPAI‑PTF to reference cryptographic algorithms in a consistent, interoperable, and implementation‑independent manner. It provides canonical names for hash algorithms, signature algorithms, encryption algorithms, key‑establishment algorithms, and other security‑relevant primitives used across PTF data types such as credentials, evidence, policies, and profiles.
The taxonomy ensures that all PTF components refer to cryptographic algorithms using stable identifiers rather than implementation‑specific labels, enabling interoperability, validation, and policy enforcement across heterogeneous systems.
2 Functional Requirements
The Security Algorithm Taxonomy shall:
- Provide unique, stable identifiers for each cryptographic algorithm used within PTF.
- Classify algorithms into categories such as:
- Hash algorithms
- Signature algorithms
- Encryption algorithms
- Key‑establishment algorithms
- Message authentication algorithms
- Custom or externally defined algorithms
- Support algorithm agility, allowing new algorithms to be added without breaking existing implementations.
- Provide identifiers that are independent of vendor, library, or platform.
- Enable PTF components to:
- Declare which algorithms they require (e.g., in PolicyBinding, Profile).
- Declare which algorithms they support (e.g., in CapabilityProfile).
- Declare which algorithms they use (e.g., in CII, InstanceCredential, AttestationEvidence).
- Allow referencing of post‑quantum, hybrid, and future algorithms.
- Support custom algorithm identifiers for deployments requiring non‑standard or proprietary algorithms.
- Ensure that identifiers are:
- Human‑readable
- Machine‑processable
- Version‑stable
- Provide a single authoritative namespace for all PTF cryptographic algorithm identifiers.
3 Syntax
https://schemas.mpai.community/PTF/V1.0/data/SecurityAlgorithmTaxonomy.json
4 Semantics
| Label | Description |
|---|---|
| Hash | Identifies allowed hash algorithms. |
| – AIF-ALGO-HASH-SHA256 | SHA‑256 hash algorithm. |
| – AIF-ALGO-HASH-SHA384 | SHA‑384 hash algorithm. |
| – AIF-ALGO-HASH-SHA512 | SHA‑512 hash algorithm. |
| – AIF-ALGO-HASH-SHA3-256 | SHA‑3‑256 hash algorithm. |
| – AIF-ALGO-HASH-SHA3-512 | SHA‑3‑512 hash algorithm. |
| – AIF-ALGO-HASH-BLAKE3 | BLAKE3 hash algorithm. |
| – AIF-ALGO-HASH-CUSTOM | Implementation‑specific hash algorithm. |
| Signature | Identifies allowed signature algorithms. |
| – AIF-ALGO-SIG-ED25519 | Ed25519 signature algorithm. |
| – AIF-ALGO-SIG-ECDSA-P256-SHA256 | ECDSA P‑256 with SHA‑256. |
| – AIF-ALGO-SIG-ECDSA-P384-SHA384 | ECDSA P‑384 with SHA‑384. |
| – AIF-ALGO-SIG-RSA-PSS-SHA256 | RSA‑PSS using SHA‑256. |
| – AIF-ALGO-SIG-RSA-PSS-SHA384 | RSA‑PSS using SHA‑384. |
| – AIF-ALGO-SIG-DILITHIUM2 | Dilithium‑2 post‑quantum signature algorithm. |
| – AIF-ALGO-SIG-FALCON512 | Falcon‑512 post‑quantum signature algorithm. |
| – AIF-ALGO-SIG-CUSTOM | Implementation‑specific signature algorithm. |
| MAC | Identifies allowed message authentication code algorithms. |
| – AIF-ALGO-MAC-HMAC-SHA256 | HMAC using SHA‑256. |
| – AIF-ALGO-MAC-HMAC-SHA384 | HMAC using SHA‑384. |
| – AIF-ALGO-MAC-CMAC-AES | CMAC using AES. |
| – AIF-ALGO-MAC-CUSTOM | Implementation‑specific MAC algorithm. |
| Encryption | Identifies allowed symmetric encryption algorithms. |
| – AIF-ALGO-ENC-AES-256-CBC | AES‑256‑CBC encryption. |
| – AIF-ALGO-ENC-AES-256-CTR | AES‑256‑CTR encryption. |
| – AIF-ALGO-ENC-CHACHA20 | ChaCha20 encryption. |
| – AIF-ALGO-ENC-CUSTOM | Implementation‑specific encryption algorithm. |
| AEAD | Identifies allowed authenticated-encryption-with-associated-data algorithms. |
| – AIF-ALGO-AEAD-AES-256-GCM | AES‑256‑GCM authenticated encryption. |
| – AIF-ALGO-AEAD-CHACHA20-POLY1305 | ChaCha20‑Poly1305 authenticated encryption. |
| – AIF-ALGO-AEAD-CUSTOM | Implementation‑specific AEAD algorithm. |
| KeyExchange | Identifies allowed key‑exchange or key‑agreement algorithms. |
| – AIF-ALGO-KX-X25519 | X25519 key exchange. |
| – AIF-ALGO-KX-ECDH-P256 | ECDH using P‑256. |
| – AIF-ALGO-KX-ECDH-P384 | ECDH using P‑384. |
| – AIF-ALGO-KX-KYBER512 | Kyber‑512 post‑quantum key encapsulation. |
| – AIF-ALGO-KX-CUSTOM | Implementation‑specific key‑exchange algorithm. |
| Hybrid | Identifies allowed hybrid classical + post‑quantum algorithms. |
| – AIF-ALGO-HYBRID-X25519-KYBER512 | Hybrid X25519 + Kyber‑512. |
| – AIF-ALGO-HYBRID-ECDH-P256-DILITHIUM2 | Hybrid ECDH‑P256 + Dilithium‑2. |
| – AIF-ALGO-HYBRID-CUSTOM | Implementation‑specific hybrid algorithm. |