Developer Reference

Contents

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.
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 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.)

Product and Performance Information

1

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