GFpECVerifyNR¶

Verifies authenticity of the digital signature over a message digest (the Nyberg-Rueppel scheme).

Syntax¶

IppStatus ippsGFpECVerifyNR(onst IppsBigNumState* pMsgDigest, const IppsGFpECPoint* pRegPublic, const IppsBigNumState* pSignR, const IppsBigNumState* pSignS, IppECResult* pResult, IppsGFpECState* pEC, Ipp8u* pScratchBuffer);

Include Files¶

ippcp.h

Parameters¶

pMsgDigest	Pointer to the message digest `msg`.
pRegPublic	Pointer to the signer’s regular public key.
pSignR	Pointer to the integer `r` of the digital signature.
pSignS	Pointer to the integer `s` of the digital signature.
pResult	Pointer to the digital signature verification result.
pEC	Pointer to the context of the elliptic curve.
pScratchBuffer	Pointer to the scratch buffer.

Description¶

The function verifies authenticity of the digital signature over a message digest msg. The signature consists of two large integers: r and s.

The scheme used to compute the digital signature is an elliptic curve analogue of the El-Gamal Digital Signature scheme with the message recovery (the Nyberg-Rueppel signature scheme).

You can get the message sender’s regular public key regPubKey by calling the function GFpECPublicKey.

The result of the digital signature verification can take one of two possible values:

ippECValid	Digital signature is valid.
ippECInvalidSignature	Digital signature is not valid.

The call to the GFpECVerifyNR function must be preceded by a call to the GFpECSignNR function which computes the digital signature over the message digest msg and represents the signature with two numbers: r and s.

The elliptic curve domain parameters must be hitherto defined by the functions: GFpECInitStd, GFpECInit, GFpECSet, or GFpECSetSubgroup.

For more information on digital signatures, please refer to the [ANSI] standard.

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 pMsgDigest, pRegPublic, pSignR, pSignS, or pEC does not match the operation.
ippStsMessageErr	Indicates an error condition if the value of `msg` pointed to by pMsgDigest falls outside the range of [1, `n`-1] where `n` is the order of the elliptic curve base point `G`.
ippStsRangeErr	Indicates an error condition if any of the parameters pointed to by pSignR or pSignS is negative.
ippStsOutOfRangeErr	Indicates an error condition if the public key point does not belong to the finite field over which the elliptic curve is initialized.
ippStsNotSupportedModeErr	Indicates an error condition if the finite field GFp under the elliptic curve is not prime.

Intel® Integrated Performance Primitives Cryptography documentation