elgamal.h File Reference

ElGamal algorithm. More...

#include "beecrypt/mpbarrett.h"

Include dependency graph for elgamal.h:

Go to the source code of this file.

Functions
int	elgv1sign (const mpbarrett *p, const mpbarrett *n, const mpnumber *g, randomGeneratorContext *, const mpnumber *hm, const mpnumber *x, mpnumber *r, mpnumber *s)
	This function performs raw ElGamal signing, variant 1.
int	elgv3sign (const mpbarrett *p, const mpbarrett *n, const mpnumber *g, randomGeneratorContext *, const mpnumber *hm, const mpnumber *x, mpnumber *r, mpnumber *s)
	This function performs raw ElGamal signing, variant 3.
int	elgv1vrfy (const mpbarrett *p, const mpbarrett *n, const mpnumber *g, const mpnumber *hm, const mpnumber *y, const mpnumber *r, const mpnumber *s)
	This function performs raw ElGamal verification, variant 1.
int	elgv3vrfy (const mpbarrett *p, const mpbarrett *n, const mpnumber *g, const mpnumber *hm, const mpnumber *y, const mpnumber *r, const mpnumber *s)
	This function performs raw ElGamal verification, variant 3.

Detailed Description

ElGamal algorithm.

For more information on this algorithm, see: "Handbook of Applied Cryptography", 11.5.2: "The ElGamal signature scheme", p. 454-459

Two of the signature variants in Note 11.70 are implemented.

Todo

Implement ElGamal encryption and decryption.

Todo

Explore the possibility of using simultaneous multiple exponentiation, as described in HAC, 14.87 (iii).

Author

Bob Deblier bob.d.nosp@m.ebli.nosp@m.er@te.nosp@m.lene.nosp@m.t.be

Function Documentation

elgv1sign()

int elgv1sign	(	const mpbarrett *	p,
		const mpbarrett *	n,
		const mpnumber *	g,
		randomGeneratorContext *	rgc,
		const mpnumber *	hm,
		const mpnumber *	x,
		mpnumber *	r,
		mpnumber *	s )

This function performs raw ElGamal signing, variant 1.

Signing equations:

• 
• 

Parameters

p	The prime.
n	The reducer mod (p-1).
g	The generator.
rgc	The pseudo-random generat
hm	The hash to be signed.
x	The private key value.
r	The signature's r value.
s	The signature's s value.

Return values

0	on success.
-1	on failure.

References BEECRYPTAPI.

elgv1vrfy()

int elgv1vrfy	(	const mpbarrett *	p,
		const mpbarrett *	n,
		const mpnumber *	g,
		const mpnumber *	hm,
		const mpnumber *	y,
		const mpnumber *	r,
		const mpnumber *	s )

This function performs raw ElGamal verification, variant 1.

Verifying equations:

• Check and
• 
• 
• Check

Parameters

p	The prime.
n	The reducer mod (p-1).
g	The generator.
hm	The hash to be signed.
y	The public key value.
r	The signature's r value.
s	The signature's s value.

Return values

1	on success.
0	on failure.

References BEECRYPTAPI.

elgv3sign()

int elgv3sign	(	const mpbarrett *	p,
		const mpbarrett *	n,
		const mpnumber *	g,
		randomGeneratorContext *	rgc,
		const mpnumber *	hm,
		const mpnumber *	x,
		mpnumber *	r,
		mpnumber *	s )

This function performs raw ElGamal signing, variant 3.

Signing equations:

• 
• 

Parameters

p	The prime.
n	The reducer mod (p-1).
g	The generator.
rgc	The pseudo-random generat
hm	The hash to be signed.
x	The private key value.
r	The signature's r value.
s	The signature's s value.

Return values

0	on success.
-1	on failure.

References BEECRYPTAPI.

elgv3vrfy()

int elgv3vrfy	(	const mpbarrett *	p,
		const mpbarrett *	n,
		const mpnumber *	g,
		const mpnumber *	hm,
		const mpnumber *	y,
		const mpnumber *	r,
		const mpnumber *	s )

This function performs raw ElGamal verification, variant 3.

Verifying equations:

• Check and
• 
• 
• Check

Parameters

p	The prime.
n	The reducer mod (p-1).
g	The generator.
hm	The hash to be signed.
y	The public key value.
r	The signature's r value.
s	The signature's s value.

Return values

1	on success.
0	on failure.