Visible to Intel only — GUID: GUID-B915BCF6-B9AF-4AF8-B269-63947DB39B4C
Visible to Intel only — GUID: GUID-B915BCF6-B9AF-4AF8-B269-63947DB39B4C
GFpECPSharedSecretDH, GFpECPSharedSecretDHC
Computes a shared secret field element by using the Diffie-Hellman scheme.
Syntax
IppStatus ippsGFpECSharedSecretDH(const IppsBigNumState* pPrivateA, const IppsGFpECPoint* pPublicB, IppsBigNumState* pShare, IppsGFpECState* pEC, Ipp8u* pScratchBuffer);
IppStatus ippsGFpECSharedSecretDHC(const IppsBigNumState* pPrivateA, const IppsGFpECPoint* pPublicB, IppsBigNumState* pShare, IppsGFpECState* pEC, Ipp8u* pScratchBuffer);
Include Files
ippcp.h
Parameters
pPrivateA |
Pointer to your own private key privKey. |
pPublicB |
Pointer to the public key pubKey. |
pShare |
Pointer to the secret number bnShare. |
pEC |
Pointer to the context of the elliptic curve. |
pScratchBuffer |
Pointer to the scratch buffer of size produced by ippsGFpECScratchBufferSize. |
Description
The function computes a secret number bnShare, which is a secret key shared between two participants of the cryptosystem.
The ippsGFpECSharedSecretDH function computes elliptic point P =[pPrivateA]· pPublicB. In the ippsGFpECSharedSecretDHC function the h cofactor is used: P =[h][pPrivateA]· pPublicB.
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 one of the contexts pointed to by pPublicB, pPrivateA, pShare, or pEC is not valid. |
ippStsRangeErr |
Indicates an error condition if the memory size of bnShare pointed to by pShare is less than the size of the GFp modulus that is base for the specified elliptic curve. |
ippStsShareKeyErr |
Indicates an error condition if the shared secret key is not valid. (For example, the shared secret key is invalid if the result of the secret point calculation is the point at infinity.) |