crystals-go/crystals-kyber/params.go

package kyber

//The first block of constants define internal parameters.
//SEEDBYTES holds the lenght in byte of the random number to give as input, if wanted.
//The remaining constants are exported to allow for fixed-lenght array instantiation. For a given security level, the consts are the same as the output of the k.SIZEX() functions defined in keys.go
const (
	n            = 256
	q            = 3329
	qInv         = 62209
	eta2         = 2
	shake128Rate = 168
	polysize     = 384

	SIZEZ             = 32
	SEEDBYTES         = 32
	Kyber512SizePK    = 800
	Kyber512SizeSK    = 1632
	Kyber512SizePKESK = 768
	Kyber512SizeC     = 768 //2*320 + 128

	Kyber768SizePK    = 1184
	Kyber768SizeSK    = 2400
	Kyber768SizePKESK = 1152
	Kyber768SizeC     = 1088 //3*320 + 128

	Kyber1024SizePK    = 1568
	Kyber1024SizeSK    = 3168
	Kyber1024SizePKESK = 1536
	Kyber1024SizeC     = 1568 //4*352 + 160
)

//Kyber struct defines the internal parameters to be used given a security level
type Kyber struct {
	Name   string
	params *parameters
}

//parameters hold all internal varying parameters used in a kyber scheme
type parameters struct {
	K         int
	ETA1      int
	DU        int
	DV        int
	SIZEPK    int //= K*POLYSIZE + SEEDBYTES
	SIZESK    int //= SIZEZ + 32 + SIZEPK + K*POLYSIZE
	SIZEPKESK int //= K * POLYSIZE
	SIZEC     int
}

//NewKyber512 defines a kyber instance with a light security level.
func NewKyber512() *Kyber {
	return &Kyber{
		Name: "Kyber512",
		params: &parameters{
			K:         2,
			ETA1:      3,
			DU:        10,
			DV:        4,
			SIZEPK:    800,
			SIZESK:    1632,
			SIZEPKESK: 768,
			SIZEC:     2*320 + 128,
		}}
}

//NewKyber768 defines a kyber instance with a medium security level.
func NewKyber768() *Kyber {
	return &Kyber{
		Name: "Kyber768",
		params: &parameters{
			K:         3,
			ETA1:      2,
			DU:        10,
			DV:        4,
			SIZEPK:    1184,
			SIZESK:    2400,
			SIZEPKESK: 1152,
			SIZEC:     3*320 + 128,
		}}
}

//NewKyber1024 defines a kyber instance with a very high security level.
func NewKyber1024() *Kyber {
	return &Kyber{
		Name: "Kyber1024",
		params: &parameters{
			K:         4,
			ETA1:      2,
			DU:        11,
			DV:        5,
			SIZEPK:    1568,
			SIZESK:    3168,
			SIZEPKESK: 1536,
			SIZEC:     4*352 + 160,
		}}
}

//NewKyberUnsafe is a skeleton function to be used for research purposes when wanting to use a kyber instance with parameters that differ from the recommended ones.
func NewKyberUnsafe(n, k, q, eta1, et2, du, dv int) *Kyber {
	return &Kyber{
		Name:   "Custom Kyber",
		params: &parameters{},
	}
}