Visible to Intel only — GUID: GUID-BF380622-360C-4085-BA2F-E1B228CF4B0F
Visible to Intel only — GUID: GUID-BF380622-360C-4085-BA2F-E1B228CF4B0F
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 key privKey. |
pPublic |
Pointer to the public key pubKey. |
pEC |
Pointer to the context of the elliptic curve. |
pScratchBuffer |
Pointer to the scratch buffer of size produced by ippsGFpECScratchBufferSize. |
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.
The ippsGFpECScratchBufferSize function should be called with nScalars equal to at least 1 to get the valid pScratchBuffer.
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 any of the contexts pointed to by pPrivate, pPublic, or pEC does 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 if pPublic does not belong to the finite field that the elliptic curve is initialized over. |