Skip to content

Supported keys

LAAVAT PKI and Signing Platform supports following keys and hash algorithms.

Key Type Key Size/Curve Hash Algorithm NIST Recommended Notes
AES 128 bits N/A Yes
AES 256 bits N/A Yes
Passphrase 32 bytes N/A N/A Used for firmware update encryption
RSA 1024 bits SHA-256 No Legacy, not recommended
RSA 1024 bits SHA-512 No Legacy, not recommended
RSA 2048 bits SHA-256 No
RSA 2048 bits SHA-512 No
RSA 3072 bits SHA-256 Yes
RSA 3072 bits SHA-512 Yes
RSA 4096 bits SHA-256 Yes
RSA 4096 bits SHA-512 Yes
EC secp224r1 SHA-256 No
EC secp224r1 SHA-512 No
EC secp256r1 SHA-256 Yes
EC secp256r1 SHA-512 Yes
EC secp384r1 SHA-256 No
EC secp384r1 SHA-512 Yes
EC secp521r1 SHA-256 No
EC secp521r1 SHA-512 Yes
ML-DSA ML-DSA-44 None Yes Post-quantum (FIPS 204), see below
ML-DSA ML-DSA-65 None Yes Post-quantum (FIPS 204), see below
ML-DSA ML-DSA-87 None Yes Post-quantum (FIPS 204), see below

Post-quantum: ML-DSA

ML-DSA (FIPS 204) is the NIST post-quantum signature standard. The platform supports the three parameter sets as the key types MLDSA44, MLDSA65 and MLDSA87.

Key type Security category Public key Signature
MLDSA44 2 1312 bytes 2420 bytes
MLDSA65 3 1952 bytes 3309 bytes
MLDSA87 5 2592 bytes 4627 bytes

What an ML-DSA key can do:

  • Certificates: CA and end-entity keys in a PKI hierarchy, and the certificates, CSRs and CRLs they sign. A CA with an ML-DSA key can also issue certificates for RSA and EC keys. See the PKI guide.
  • Message signing: a DigestSigning operation with an ML-DSA key signs the message itself instead of a digest. See Signing with ML-DSA keys.
  • NXP AHAB: MLDSA65 and MLDSA87 SRK keys with SPSDK signing. See SPSDK signing.

What differs from RSA and EC keys:

  • There is no separate hash algorithm. ML-DSA signs the whole message, so the hash algorithm is NONE and the signature padding is NONE.
  • ML-DSA keys are HSM keys only. They cannot be software-protected, and they are not available as an exportable token.
  • The signature format is the raw FIPS 204 signature. The CMS format is not available.
  • Verifying needs a library that implements FIPS 204, for example OpenSSL 3.5 or later.

Hash algorithms

The platform schema defines SHA-256 and SHA-512 as supported hash algorithms. SHA-384 may be available at the implementation level for specific signing operations (CMS, JAR, Windows signing) but is not part of the core schema enum.