crsyspqc::Kem Class Reference

Key-Encapsulation Mechanism (KEM) methods. More...

Classes
struct	EncapOutput
	Structure to receive KEM encapsulation output (ss, ct) More...
struct	KeyPair
	Structure to receive a key pair (ek, dk) More...

Public Types
enum class	Alg
	Key-Encapsulation Mechanism (KEM) algorithm. More...

Static Public Member Functions
static KeyPair	KeyGen (Alg alg, const std::string &params="")
	Generate an encapsulation/decapsulation key pair (ek, dk). More...
static EncapOutput	Encaps (Alg alg, bvec_t ek, const std::string &params="")
	Carry out the KEM encapsulation algorithm. More...
static bvec_t	Decaps (Alg alg, bvec_t ct, bvec_t dk)
	Carry out the KEM decapsulation algorithm. More...
static int	EncapKeySize (Alg alg)
	Return length of encapulation ("public") key ek in bytes.
static int	DecapKeySize (Alg alg)
	Return length of expanded decapulation ("private") key dk in bytes.
static int	CipherTextSize (Alg alg)
	Return length of ciphertext ct in bytes.
static int	SharedKeySize (Alg alg)
	Return length of shared secret key ss (K) in bytes.
static std::string	AlgName (Alg alg)
	Get algorithm name from its alg code.

Detailed Description

Key-Encapsulation Mechanism (KEM) methods.

Member Enumeration Documentation

Alg

enum crsyspqc::Kem::Alg

strong

Key-Encapsulation Mechanism (KEM) algorithm.

Enumerator
ML_KEM_512	ML-KEM-512 from FIPS.203 (based on Kyber512)
ML_KEM_768	ML-KEM-768 from FIPS.203 (based on Kyber768)
ML_KEM_1024	ML-KEM-1024 from FIPS.203 (based on Kyber1024)

Member Function Documentation

KeyGen()

static KeyPair crsyspqc::Kem::KeyGen ( Alg  alg, const std::string &  params = ""  )

static

Generate an encapsulation/decapsulation key pair (ek, dk).

Parameters

alg	KEM algorithm.
params	Optional parameters string. Use to pass a known test random value encoded in hexadecimal. [default = add fresh randomness].

Returns

Key pair in Kem::KeyPair structure.

Encaps()

static EncapOutput crsyspqc::Kem::Encaps ( Alg  alg, bvec_t  ek, const std::string &  params = ""  )

static

Carry out the KEM encapsulation algorithm.

Parameters

alg	KEM algorithm.
ek	Encapsulation key.
params	Optional parameters string. Use to pass a known test random value encoded in hexadecimal. [default = add fresh randomness].

Returns

Shared secret key (ss) and ciphertext (ct) in Kem::EncapOutput structure.

Decaps()

static bvec_t crsyspqc::Kem::Decaps ( Alg  alg, bvec_t  ct, bvec_t  dk  )

static

Carry out the KEM decapsulation algorithm.

Parameters

alg	KEM algorithm.
ct	Ciphertext (ct) in a byte array.
dk	Decapsulation key.

Returns

Shared secret key (ss) in a byte array. On failure it will contain a pseudo-random value.

Remarks

The decapsulation (private) key dk may be passed in expanded form (1632|2400|3168 bytes) or as a 64-byte seed. The key form is detected automatically by its length.