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:

[legend]List of all members.

Public Member Functions
	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 BIGNUM%s.
	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 BigNumber%s.
	ElGamalSchnorrCipherText (const ElGamalSchnorrCipherText &aCT)
	Copy constructor.
virtual	~ElGamalSchnorrCipherText ()
	Destructor.
void	operator= (const ElGamalSchnorrCipherText &aCT)
	Assignment operator.
const CODEX_ASN1::BigNumber &	h () const
	Hash value from Schnorr signature.
const CODEX_ASN1::BigNumber &	z () const
	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.
bool	operator< (const ElGamalCipherText &aCT) const
	Less-than operator.
bool	operator== (const ElGamalCipherText &aCT) const
	Equality operator.
bool	operator!= (const ElGamalCipherText &aCT) const
	Inequality operator.
const CODEX_ASN1::BigNumber &	c1 () const
	First part of the ciphertext -- g^k mod p.
const CODEX_ASN1::BigNumber &	c2 () const
	Second part of the ciphertext -- m y^k mod p.
ElGamalCipherText *	blind (const ElGamalCipherText &aOther, const CODEX_ASN1::BigNumber &modulus) const
	Blind a ciphertext.
bool	initialized () const
Protected Attributes
bool	m_initialized
	Has this object been initialized yet, or is it still blank?

---

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 97 of file ElGamal.h.

---

Member Function Documentation

ElGamalCipherText * ElGamalCipherText::blind (  const ElGamalCipherText &  aOther, const CODEX_ASN1::BigNumber &  modulus )  const [inherited]

Blind a ciphertext. Parameters: aOther  Another ciphertext modulus  The modulus for the group in which ciphertexts live Returns: A pointer to a new ciphertext which is the product of the current ciphertext and the one passed in. Definition at line 90 of file ElGamalCipherText.cc. References CODEX_Ciphers::ElGamalCipherText::ElGamalCipherText(), and CODEX_ASN1::BigNumber::value().

bool CODEX_ASN1::Base::initialized (   )  const [inline, inherited]

Returns: Has this object been initialized? Definition at line 175 of file Base.h. References CODEX_ASN1::Base::m_initialized. Referenced by CODEX_APSS::SecretManagement::addComputeMsg(), CODEX_APSS::SecretManagement::addEstablishMsg(), CODEX_APSS::SecretManagement::addEstablishResponse(), CODEX_APSS::SecretManagement::addInitMsg(), CODEX_APSS::SecretManagement::addSharing(), CODEX_APSS::SecretManagement::addSubsharing(), CODEX_VSS::Combinatoric< NumT, ThreshT >::apply(), CODEX_Server::ServerState::caKey(), CODEX_KeyService::ClientCreateCallback::ClientCreateCallback(), CODEX_VSS::Combinatoric< NumT, ThreshT >::count(), CODEX_Server::QuorumBuilderAct::handler(), CODEX_APSS::MessageVerifier::handler(), CODEX_KeyService::DelegateResponseVerifier::handler(), CODEX_KeyService::DelegateRequestDistributor::handler(), CODEX_KeyService::ClientMessageVerifier::handler(), CODEX_KeyService::ClientMessageSigner::handler(), CODEX_VSS::SubshareLabel< LabelType >::marshal(), CODEX_KeyService::KeyInfo::marshal(), CODEX_VSS::LabeledShare< ShareType, OneWay >::marshal(), CODEX_VSS::ShareLabel< _ShareType, _OneWay >::marshal(), CODEX_VSS::ModExpFunctionalArgs::marshal(), CODEX_VSS::Combinatoric< NumT, ThreshT >::marshal(), CODEX_KeyService::SignWriteCallback::operator()(), CODEX_KeyService::SignReadCallback::operator()(), CODEX_KeyService::SignCreateCallback::operator()(), CODEX_VSS::ModExpFunctional::operator()(), CODEX_KeyService::ClientReadCallback::operator()(), CODEX_KeyService::ClientCreateCallback::operator()(), CODEX_VSS::Combinatoric< NumT, ThreshT >::operator+=(), CODEX_Server::ServerState::readElGamalShares(), CODEX_VSS::Combinatoric< NumT, ThreshT >::recover(), CODEX_APSS::SecretManagement::sendFinished(), CODEX_Server::ServerState::serviceKey(), CODEX_Server::ServerState::setEGShareCallback(), and CODEX_Server::ServerState::setRSAShareCallback().

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::BigNumber::marshal(), CODEX_ASN1::BigNumber::value(), and z().

---

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

• ElGamal.h
• ElGamalSchnorrCipherText.cc

---