efq.h File Reference

Definition of EFq math. More...

#include <stddef.h>
#include "epid/common/bitsupplier.h"
#include "epid/common/types.h"

Functions
void	EFqMulSSCM (EccPointJacobiFq *result, EccPointJacobiFq const *base, FpElem const *exp)
	Multiply two points in EFq. More...
int	EFqAffineExp (EccPointFq *result, EccPointFq const *base, FpElem const *exp)
	Exponentiate a point in EFq by an element of Fp. More...
int	EFqAffineMultiExp (EccPointFq *result, EccPointFq const *base0, FpElem const *exp0, EccPointFq const *base1, FpElem const *exp1)
	Sum the results of exponentiating two points in EFq by elements of Fp. More...
void	EFqMultiExp (EccPointJacobiFq *result, EccPointJacobiFq const *base0, FpElem const *exp0, EccPointJacobiFq const *base1, FpElem const *exp1)
	Sum the results of exponentiating two points in EFq by elements of Fp. More...
int	EFqAffineAdd (EccPointFq *result, EccPointFq const *left, EccPointFq const *right)
	Add two points in EFq. More...
int	EFqAffineDbl (EccPointFq *result, EccPointFq const *in)
	Double a point in EFq. More...
void	EFqDbl (EccPointJacobiFq *result, EccPointJacobiFq const *in)
	Double a point in EFq. More...
void	EFqAdd (EccPointJacobiFq *result, EccPointJacobiFq const *left, EccPointJacobiFq const *right)
	Add two points in EFq. More...
int	EFqRand (EccPointFq *result, BitSupplier rnd_func, void *rnd_param)
	Generate a random point in EFq. More...
void	EFqSet (EccPointJacobiFq *result, FqElem const *x, FqElem const *y)
	Set a point's value. More...
int	EFqIsInf (EccPointJacobiFq const *in)
	Test if a point is infinity. More...
void	EFqFromAffine (EccPointJacobiFq *result, EccPointFq const *in)
	Convert a point from Affine to Jacobi representation. More...
int	EFqToAffine (EccPointFq *result, EccPointJacobiFq const *in)
	Convert a point from Jacobi to Affine representation. More...
void	EFqNeg (EccPointJacobiFq *result, EccPointJacobiFq const *in)
	Negate a point on EFq. More...
int	EFqEq (EccPointJacobiFq const *left, EccPointJacobiFq const *right)
	Test if two points on EFq are equal. More...
int	EFqHash (EccPointFq *result, unsigned char const *msg, size_t len, HashAlg hashalg)
	Hashes an arbitrary message to a point on EFq. More...
void	EFqCp (EccPointFq *result, EccPointFq const *in)
	Copy a point's value. More...
int	EFqEqAffine (EccPointFq const *left, EccPointFq const *right)
	Test if two points on EFq are equal. More...
void	EFqCondSet (EccPointJacobiFq *result, EccPointJacobiFq const *true_val, EccPointJacobiFq const *false_val, int truth_val)
	Conditionally Set a point's value to one of two values. More...
void	EFqJCp (EccPointJacobiFq *result, EccPointJacobiFq const *in)
	Copy a point's value. More...
void	EFqInf (EccPointJacobiFq *result)
	Set an element's value to infinity. More...
int	EFqOnCurve (EccPointFq const *in)
	Test if a point is on EFq. More...
int	EFqJOnCurve (EccPointJacobiFq const *in)
	Test if a point is on EFq. More...
int	EFqJRand (EccPointJacobiFq *result, BitSupplier rnd_func, void *rnd_param)
	Generate a random point in EFq. More...

Detailed Description

Definition of EFq math.

Function Documentation

EFqAdd()

void EFqAdd	(	EccPointJacobiFq *	result,
		EccPointJacobiFq const *	left,
		EccPointJacobiFq const *	right
	)

Add two points in EFq.

Parameters

[out]	result	of adding left and right.
[in]	left	The first operand to be added.
[in]	right	The second operand to be added.

EFqAffineAdd()

int EFqAffineAdd	(	EccPointFq *	result,
		EccPointFq const *	left,
		EccPointFq const *	right
	)

Add two points in EFq.

Parameters

[out]	result	of adding left and right.
[in]	left	The first operand to be added.
[in]	right	The second operand to be added.

Returns

A value different from zero (i.e., true) if on success. Zero (i.e., false) otherwise.

EFqAffineDbl()

int EFqAffineDbl	(	EccPointFq *	result,
		EccPointFq const *	in
	)

Double a point in EFq.

Parameters

[out]	result	target.
[in]	in	the value to double.

Returns

A value different from zero (i.e., true) if on success. Zero (i.e., false) otherwise.

EFqAffineExp()

int EFqAffineExp	(	EccPointFq *	result,
		EccPointFq const *	base,
		FpElem const *	exp
	)

Exponentiate a point in EFq by an element of Fp.

Parameters

[out]	result	target.
[in]	base	the base.
[in]	exp	the exponent.

Returns

A value different from zero (i.e., true) if on success. Zero (i.e., false) otherwise.

1 on success, 0 on failure

EFqAffineMultiExp()

int EFqAffineMultiExp	(	EccPointFq *	result,
		EccPointFq const *	base0,
		FpElem const *	exp0,
		EccPointFq const *	base1,
		FpElem const *	exp1
	)

Sum the results of exponentiating two points in EFq by elements of Fp.

Parameters

[out]	result	target.
[in]	base0	the first base.
[in]	exp0	the first exponent.
[in]	base1	the second base.
[in]	exp1	the second exponent.

Returns

A value different from zero (i.e., true) if on success. Zero (i.e., false) otherwise.

EFqCondSet()

void EFqCondSet	(	EccPointJacobiFq *	result,
		EccPointJacobiFq const *	true_val,
		EccPointJacobiFq const *	false_val,
		int	truth_val
	)

Conditionally Set a point's value to one of two values.

Parameters

[out]	result	target.
[in]	true_val	value to set if condition is true.
[in]	false_val	value to set if condition is false.
[in]	truth_val	value of condition.

EFqCp()

void EFqCp	(	EccPointFq *	result,
		EccPointFq const *	in
	)

Copy a point's value.

Parameters

[out]	result	copy target.
[in]	in	copy source.

EFqDbl()

void EFqDbl	(	EccPointJacobiFq *	result,
		EccPointJacobiFq const *	in
	)

Double a point in EFq.

Parameters

[out]	result	target.
[in]	in	the value to double.

EFqEq()

int EFqEq	(	EccPointJacobiFq const *	left,
		EccPointJacobiFq const *	right
	)

Test if two points on EFq are equal.

Parameters

[in]	left	The first operand to be tested.
[in]	right	The second operand to be tested.

Returns

A value different from zero (i.e., true) if indeed the values are equal. Zero (i.e., false) otherwise.

EFqEqAffine()

int EFqEqAffine	(	EccPointFq const *	left,
		EccPointFq const *	right
	)

Test if two points on EFq are equal.

Parameters

[in]	left	The first operand to be tested.
[in]	right	The second operand to be tested.

Returns

A value different from zero (i.e., true) if indeed the values are equal. Zero (i.e., false) otherwise.

EFqFromAffine()

void EFqFromAffine	(	EccPointJacobiFq *	result,
		EccPointFq const *	in
	)

Convert a point from Affine to Jacobi representation.

Parameters

[out]	result	target.
[in]	in	value to set.

EFqHash()

int EFqHash	(	EccPointFq *	result,
		unsigned char const *	msg,
		size_t	len,
		HashAlg	hashalg
	)

Hashes an arbitrary message to a point on EFq.

Parameters

[out]	result	target.
[in]	msg	buffer to reinterpret.
[in]	len	length of msg in bytes.
[in]	hashalg	hash algorithm to use.

Returns

A value different from zero (i.e., true) if on success. Zero (i.e., false) otherwise.

EFqInf()

void EFqInf

(

EccPointJacobiFq *

result

)

Set an element's value to infinity.

Parameters

[out]

result

element to set.

EFqIsInf()

int EFqIsInf

(

EccPointJacobiFq const *

in

)

Test if a point is infinity.

Parameters

[in]

in

the point to test.

Returns

A value different from zero (i.e., true) indeed the value is infinity. Zero (i.e., false) otherwise.

EFqJCp()

void EFqJCp	(	EccPointJacobiFq *	result,
		EccPointJacobiFq const *	in
	)

Copy a point's value.

Parameters

[out]	result	copy target.
[in]	in	copy source.

EFqJOnCurve()

int EFqJOnCurve

(

EccPointJacobiFq const *

in

)

Test if a point is on EFq.

Parameters

[in]

in

the point to test.

Returns

A value different from zero (i.e., true) indeed the point is on the curve. Zero (i.e., false) otherwise.

EFqJRand()

int EFqJRand	(	EccPointJacobiFq *	result,
		BitSupplier	rnd_func,
		void *	rnd_param
	)

Generate a random point in EFq.

Parameters

[in]	result	the random value.
[in]	rnd_func	Random number generator.
[in]	rnd_param	Pass through context data for rnd_func.

Returns

A value different from zero (i.e., true) if on success. Zero (i.e., false) otherwise.

EFqMulSSCM()

void EFqMulSSCM	(	EccPointJacobiFq *	result,
		EccPointJacobiFq const *	base,
		FpElem const *	exp
	)

Multiply two points in EFq.

This function is mitigated against software side-channel attacks.

Parameters

[out]	result	of multiplying left and right.
[in]	base	The first operand to be multiplied.
[in]	exp	The second operand to be multiplied.

EFqMultiExp()

void EFqMultiExp	(	EccPointJacobiFq *	result,
		EccPointJacobiFq const *	base0,
		FpElem const *	exp0,
		EccPointJacobiFq const *	base1,
		FpElem const *	exp1
	)

Sum the results of exponentiating two points in EFq by elements of Fp.

Parameters

[out]	result	target.
[in]	base0	the first base.
[in]	exp0	the first exponent.
[in]	base1	the second base.
[in]	exp1	the second exponent.

Returns

1 on success, 0 on failure

EFqNeg()

void EFqNeg	(	EccPointJacobiFq *	result,
		EccPointJacobiFq const *	in
	)

Negate a point on EFq.

Parameters

[out]	result	the negative of the element.
[in]	in	the element to negate.

EFqOnCurve()

int EFqOnCurve

(

EccPointFq const *

in

)

Test if a point is on EFq.

Parameters

[in]

in

the point to test.

Returns

A value different from zero (i.e., true) indeed the point is on the curve. Zero (i.e., false) otherwise.

EFqRand()

int EFqRand	(	EccPointFq *	result,
		BitSupplier	rnd_func,
		void *	rnd_param
	)

Generate a random point in EFq.

Parameters

[in]	result	the random value.
[in]	rnd_func	Random number generator.
[in]	rnd_param	Pass through context data for rnd_func.

Returns

A value different from zero (i.e., true) if on success. Zero (i.e., false) otherwise.

EFqSet()

void EFqSet	(	EccPointJacobiFq *	result,
		FqElem const *	x,
		FqElem const *	y
	)

Set a point's value.

Parameters

[out]	result	target.
[in]	x	value to set.
[in]	y	value to set.

EFqToAffine()

int EFqToAffine	(	EccPointFq *	result,
		EccPointJacobiFq const *	in
	)

Convert a point from Jacobi to Affine representation.

Parameters

[out]	result	target.
[in]	in	value to set.

Returns

A value different from zero (i.e., true) if on success. Zero (i.e., false) otherwise.