GFpECPSharedSecretDH, GFpECPSharedSecretDHC
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 keyprivKey.
- pPublicB
- Pointer to the public keypubKey.
- pShare
- Pointer to the secret numberbnShare.
- pEC
- Pointer to the context of the elliptic curve.
- pScratchBuffer
- Pointer to the scratch buffer.
Description
The function computes a secret number
bnShare
, which is a secret key shared between two participants of the cryptosystem. The
ippsGFpECPSharedSecretDH
function computes elliptic point P =
[pPrivateA]
·
pPublicB
. In the ippsGFpECPSharedSecretDHC
function the h
cofactor is used: P =
[h]
[pPrivateA]
·
pPublicB
.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 one of the contexts pointed to bypPublicB,pPrivateA,pShare, orpECis not valid.
- ippStsRangeErr
- Indicates an error condition if the memory size ofbnSharepointed to bypShareis 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.)