Contents

# ECCPSet

Sets up elliptic curve domain parameters over GF(p).

## Syntax

Include Files
ippcp.h
Parameters
pPrime
Pointer to the characteristic
p
of the prime finite field GF(
p
).
pA
Pointer to the coefficient
A
of the equation defining the elliptic curve.
pB
Pointer to the coefficient
B
of the equation defining the elliptic curve.
pGX
Pointer to the
x
-coordinate of the elliptic curve base point.
pGY
Pointer to the
y
-coordinate of the elliptic curve base point.
pOrder
Pointer to the order of the elliptic curve base point.
cofactor
Cofactor.
pECC
Pointer to the context of the cryptosystem.
Description
The function sets up the elliptic curve domain parameters over a prime finite field GF(
p
). These are as follows:
• pPrime
sets up the characteristic
p
of a finite field GF(
p
) where
p
is a prime number.
• pA
,
pB
set up the coefficients
A
and
B
of the equation defining the elliptic curve:
y
2
=
x
3
+
A
·
x
+
B
(mod
p
).
• pGX
,
pGY
are pointers to the affine coordinates of the elliptic curve base point
G
.
• pOrder
is a pointer to the order
n
of the elliptic curve base point
G
such that
n
·
G = O
, where
O
is the point at infinity and
n
is a prime number.
• cofactor
sets up the ratio
h
of a general number of points #E on the elliptic curve (including the point at infinity) to the order
n
of the base point:
h
= #E/
n
.
The domain parameters are set in the cryptosystem context which must be already created by the
ECCPGetSize
and
ECCPInit
functions.
Return Values
ippStsNoErr
Indicates no error. Any other value indicates an error or warning.
ippStsNullPtrErr
Indicates an error condition if any of the specified pointers is
NULL
.
ippStsContextMatchErr
Indicates an error condition if one of the contexts pointed by
pPrime
,
pA
,
pB
,
pGX
,
pGY
,
pOrder
, and
pECC
is not valid.
ippStsRangeErr
Indicates an error condition if of one of the parameters pointed by
pPrime
,
pA
,
pB
,
pGX
,
pGY
, and
pOrder
cannot embed the
feBitSize
bits length or the value of
cofactor
is less than 1.

#### Product and Performance Information

1

Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex.