GFpECPublicKey
GFpECPublicKey
Computes a public key from the given private key of the elliptic curve cryptosystem over GF(p).
Syntax
IppStatus ippsGFpECPublicKey(const IppsBigNumState*
pPrivate
, IppsGFpECPoint*
pPublic
, IppsGFpECState*
pEC
, Ipp8u*
pScratchBuffer
);
Include Files
ippcp.h
Parameters
- pPrivate
- Pointer to the private keyprivKey.
- pPublic
- Pointer to the public keypubKey.
- pEC
- Pointer to the context of the elliptic curve.
- pScratchBuffer
- Pointer to the scratch buffer.
Description
The function computes the public key
pubKey
from the given private key privKey
of the elliptic cryptosystem over a finite field GF(p
).The private key
privKey
is a number that lies in the range of [1, n
-1] where n
is the order of the elliptic curve base point. The public key pubKey
is an elliptic curve point such that pubKey
= privKey
·
G
, where G
is the base point of the elliptic curve.The private key
privKey
can be generated by the function GFpECPrivateKey.The context of the point
pubKey
as an elliptic curve point must be created by using the functions GFpECPointGetSize and GFpECPointInit.The elliptic curve domain parameters must be defined by the functions: GFpECInitStd, GFpECInit, GFpECSet, or GFpECSetSubgroup.
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 isNULL.
- ippStsContextMatchErr
- Indicates an error condition if any of the contexts pointed to bypPrivate,pPublic, orpECdoes not match the operation.
- ippStsIvalidPrivateKey
- Indicates an error condition if the value of the private key falls outside the range of [1,n-1].
- ippStsRangeErr
- Indicates an error condition ifpPublicdoes not belong to the finite field that the elliptic curve is initialized over.