org.cryptimeleon.craco.sig.ps18

Class PS18ROMSignatureScheme

java.lang.Object

org.cryptimeleon.craco.sig.ps18.PS18SignatureScheme

org.cryptimeleon.craco.sig.ps18.PS18ROMSignatureScheme

All Implemented Interfaces:

SignatureScheme, org.cryptimeleon.math.serialization.annotations.RepresentationRestorer, org.cryptimeleon.math.serialization.Representable, org.cryptimeleon.math.serialization.StandaloneRepresentable

public class PS18ROMSignatureScheme
extends PS18SignatureScheme

This class implements the signature scheme from Pointcheval and Sanders 2018 in section 4.3 where the extra m' element is computed from the message in the random oracle model. This saves one Z_p element for the signature. However, the reduction adversary has to also guess in which random oracle query the right message is, so the reduction loses a poly factor in success probability.

Constructor Summary

Constructors

Constructor and Description
PS18ROMSignatureScheme(PSPublicParameters pp)
PS18ROMSignatureScheme(org.cryptimeleon.math.serialization.Representation repr)

Method Summary

Modifier and Type	Method and Description
Signature	restoreSignature(org.cryptimeleon.math.serialization.Representation repr)
Signature	sign(PlainText plainText, SigningKey secretKey) Signs the giving plaintext using the given signing key.
java.lang.Boolean	verify(PlainText plainText, Signature signature, VerificationKey publicKey) Verifies the given signature for the given plaintext using the given verification key.

Methods inherited from class org.cryptimeleon.craco.sig.ps18.PS18SignatureScheme

computeLeftHandSide, computeSigma2, equals, generateKeyPair, getMaxNumberOfBytesForMapToPlaintext, getPp, getRepresentation, hashCode, mapToPlaintext, mapToPlaintext, mapToPlaintext, restorePlainText, restoreSigningKey, restoreVerificationKey

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.cryptimeleon.craco.sig.SignatureScheme

restoreFromRepresentation, sign, verify

Constructor Detail

PS18ROMSignatureScheme

public PS18ROMSignatureScheme(PSPublicParameters pp)

PS18ROMSignatureScheme

public PS18ROMSignatureScheme(org.cryptimeleon.math.serialization.Representation repr)

Method Detail

sign

public Signature sign(PlainText plainText,
                      SigningKey secretKey)

Description copied from interface: SignatureScheme

Signs the giving plaintext using the given signing key. The signing key should contain all information necessary to sign, therefore public key is not needed.

Specified by:

sign in interface SignatureScheme

Overrides:

sign in class PS18SignatureScheme

Parameters:

plainText - the message to sign

secretKey - the secret signing key

Returns:

signature on plainText computed using secretKey

verify

public java.lang.Boolean verify(PlainText plainText,
                                Signature signature,
                                VerificationKey publicKey)

Description copied from interface: SignatureScheme

Verifies the given signature for the given plaintext using the given verification key.

Specified by:

verify in interface SignatureScheme

Overrides:

verify in class PS18SignatureScheme

Parameters:

plainText - the plaintext the signature should validate against

signature - the signature to verify

publicKey - the verification key to verify with

Returns:

true if verification succeeds, false else

restoreSignature

public Signature restoreSignature(org.cryptimeleon.math.serialization.Representation repr)

Specified by:

restoreSignature in interface SignatureScheme

Overrides:

restoreSignature in class PS18SignatureScheme