CODEX_Ciphers::ElGamalSchnorrCipherText Class Reference

Serializable encapsulation of an ElGamal ciphertext with a Schnorr signature to prove plaintext knowledge. More...

#include <ElGamal.h>

Inheritance diagram for CODEX_Ciphers::ElGamalSchnorrCipherText:

[legend]Collaboration diagram for CODEX_Ciphers::ElGamalSchnorrCipherText:


Public Methods
	ElGamalSchnorrCipherText ()
	Default constructor, for creating an object to be unmarshalled.
	ElGamalSchnorrCipherText (BIGNUM c1, BIGNUM c2, BIGNUM h, BIGNUM z)
	Constructor taking signed ciphertext as four BIGNUMs.
	ElGamalSchnorrCipherText (const CODEX_ASN1::BigNumber &c1, const CODEX_ASN1::BigNumber &c2, const CODEX_ASN1::BigNumber &h, const CODEX_ASN1::BigNumber &z)
	Constructor taking signed ciphertext as four BigNumbers.
	ElGamalSchnorrCipherText (const ElGamalSchnorrCipherText &aCT)
	Copy constructor.
virtual	~ElGamalSchnorrCipherText ()
	Destructor.
void	operator= (const ElGamalSchnorrCipherText &aCT)
	Assignment operator.
const CODEX_ASN1::BigNumber &	h () const
	Returns: hash value from Schnorr signature
const CODEX_ASN1::BigNumber &	z () const
	Returns: Schnorr exponent
bool	verify (const CODEX_ASN1::BigNumber &g, const CODEX_ASN1::BigNumber &p, const CODEX_ASN1::Base &id, const HashFunction &hashFunc) const
	Tests the validity of a ElGamalSchnorrCipherText.
int	marshal (unsigned char **pp) const
	Serialize the object.
void *	unmarshal (void bogus, unsigned char *pp, long length)
	Unserialize the object.

Detailed Description

Serializable encapsulation of an ElGamal ciphertext with a Schnorr signature to prove plaintext knowledge.

By including the identity of the encrypting party in the signature, the ciphertext can be verified to have come from a particular principal.

Definition at line 94 of file ElGamal.h.

bool ElGamalSchnorrCipherText::verify ( const CODEX_ASN1::BigNumber & g,

const CODEX_ASN1::BigNumber & p,

const CODEX_ASN1::Base & id,

const HashFunction & hashFunc

) const

Tests the validity of a ElGamalSchnorrCipherText.
The ciphertext is used as part of the public key for the Schnorr signature.
Parameters:

g The generator from the public key used to encipher the plaintext

p The modulus of the public key

id A serializable object identifying the participant claiming to have generated the ciphertext

hashFunc A secure hash function matching that used to generate the Schnorr signature

Definition at line 71 of file ElGamalSchnorrCipherText.cc.
References CODEX_Ciphers::ElGamalCipherText::c1(), CODEX_Ciphers::ElGamalCipherText::c2(), h(), CODEX_ASN1::Base::marshal(), CODEX_ASN1::BigNumber::marshal(), CODEX_ASN1::BigNumber::value(), and z().

The documentation for this class was generated from the following files:

Generated on Wed Jun 2 16:33:04 2004 for COrnell Data EXchange (CODEX) by

1.2.18