B Algorithm and key type encoding

These are encodings for PQC algorithms and keys defined in this extension. This information should be read in conjunction with [PSA-CRYPT] Appendix B.

Note

These encodings will be integrated into a future version of [PSA-CRYPT].

B.1 Algorithm encoding

B.1.1 Hash algorithm encoding

Additional hash algorithms defined by this extension are shown in Table 4. See also Hash algorithm encoding in [PSA-CRYPT] Appendix B.

Table 4 Hash algorithm sub-type values

Hash algorithm	HASH-TYPE	Algorithm identifier	Algorithm value
SHA-256/192	0x0E	PSA_ALG_SHA_256_192	0x0200000E
SHAKE128/256	0x16	PSA_ALG_SHAKE128_256	0x02000016
SHAKE256/192	0x17	PSA_ALG_SHAKE256_192	0x02000017
SHAKE256/256	0x18	PSA_ALG_SHAKE256_256	0x02000018

B.1.2 Asymmetric signature algorithm encoding

Additional signature algorithms defined by this extension are shown in Table 5. See also Asymmetric signature algorithm encoding in [PSA-CRYPT] Appendix B.

Table 5 Asymmetric signature algorithm sub-type values

Signature algorithm	SIGN-TYPE	Algorithm identifier	Algorithm value
Hedged SLH-DSA	0x40	PSA_ALG_SLH_DSA	0x06004000
Deterministic SLH-DSA	0x41	PSA_ALG_DETERMINISTIC_SLH_DSA	0x06004100
Hedged HashSLH-DSA	0x42	PSA_ALG_HASH_SLH_DSA(hash)	0x060042hh a
Deterministic HashSLH-DSA	0x43	PSA_ALG_DETERMINISTIC_HASH_SLH_DSA(hash)	0x060043hh a
Hedged ML-DSA	0x44	PSA_ALG_ML_DSA	0x06004400
Deterministic ML-DSA	0x45	PSA_ALG_DETERMINISTIC_ML_DSA	0x06004500
Hedged HashML-DSA	0x46	PSA_ALG_HASH_ML_DSA(hash)	0x060046hh a
Deterministic HashML-DSA	0x47	PSA_ALG_DETERMINISTIC_HASH_ML_DSA(hash)	0x060047hh a
LMS	0x48	PSA_ALG_LMS	0x06004800
HSS	0x49	PSA_ALG_HSS	0x06004900
XMSS	0x4A	PSA_ALG_XMSS	0x06004A00
XMSSMT	0x4B	PSA_ALG_XMSS_MT	0x06004B00

1. hh is the HASH-TYPE for the hash algorithm, hash, used to construct the signature algorithm.

B.1.3 Key-encapsulation algorithm encoding

Additional key-encapsulation algorithms defined by this extension are shown in Table 6.

Table 6 Encapsulation algorithm sub-type values

Encapsulation algorithm	ENCAPS-TYPE	Algorithm identifier	Algorithm value
ML-KEM	0x02	PSA_ALG_ML_KEM	0x0C000200

B.2 Key encoding

Additional asymmetric key types defined by this extension are shown in Table 7. See also Asymmetric key encoding in [PSA-CRYPT] Appendix B.

Table 7 Asymmetric key sub-type values

Asymmetric key type	ASYM-TYPE	Details
SLH-DSA	3	See SLH-DSA key encoding

B.2.1 Non-parameterized asymmetric key encoding

Additional non-parameterized asymmetric key types defined by this extension are shown in Table 8. See also Non-parameterized asymmetric key encoding in [PSA-CRYPT] Appendix B.

Table 8 Non-parameterized asymmetric key family values

Key family	Public/pair	PAIR	NP-FAMILY	P	Key type	Key value
ML-DSA	Public key	0	1	0	PSA_KEY_TYPE_ML_DSA_PUBLIC_KEY	0x4002
	Key pair	3	1	0	PSA_KEY_TYPE_ML_DSA_KEY_PAIR	0x7002
ML-KEM	Public key	0	2	0	PSA_KEY_TYPE_ML_KEM_PUBLIC_KEY	0x4004
	Key pair	3	2	0	PSA_KEY_TYPE_ML_KEM_KEY_PAIR	0x7004
LMS	Public key	0	3	1	PSA_KEY_TYPE_LMS_PUBLIC_KEY	0x4007
HSS	Public key	0	4	0	PSA_KEY_TYPE_HSS_PUBLIC_KEY	0x4008
XMSS	Public key	0	5	1	PSA_KEY_TYPE_XMSS_PUBLIC_KEY	0x400B
XMSSMT	Public key	0	6	1	PSA_KEY_TYPE_XMSS_MT_PUBLIC_KEY	0x400D

B.2.2 SLH-DSA key encoding

The key type for SLH-DSA keys defined in this specification are encoded as shown in Figure 1.

Figure 1 SLH-DSA key encoding

PAIR is either 0 for a public key, or 3 for a key pair.

The defined values for FAMILY and P are shown in Table 9.

Table 9 SLH-DSA key family values

SLH-DSA key family	FAMILY	P	SLH-DSA family a	Public-key value	Key-pair value
SLH-DSA-SHA2-Ns	0x01	0	PSA_SLH_DSA_FAMILY_SHA2_S	0x4182	0x7182
SLH-DSA-SHA2-Nf	0x02	0	PSA_SLH_DSA_FAMILY_SHA2_F	0x4184	0x7184
SLH-DSA-SHAKE-Ns	0x05	1	PSA_SLH_DSA_FAMILY_SHAKE_S	0x418B	0x718B
SLH-DSA-SHAKE-Nf	0x06	1	PSA_SLH_DSA_FAMILY_SHAKE_F	0x418D	0x718D

1. The SLH-DSA family values defined in the API also include the parity bit. The key type value is constructed from the SLH-DSA family using either PSA_KEY_TYPE_SLH_DSA_PUBLIC_KEY(family) or PSA_KEY_TYPE_SLH_DSA_KEY_PAIR(family) as required.