Package org.hyperledger.fabric.sdk.idemix

Class IdemixSignature

java.lang.Object

org.hyperledger.fabric.sdk.idemix.IdemixSignature

public class IdemixSignature
extends java.lang.Object

IdemixSignature represents an idemix signature, which is a zero knowledge proof of knowledge of a BBS+ signature. The Camenisch-Drijvers-Lehmann ZKP (ia.cr/2016/663) is used

Constructor Summary

Constructors

Constructor	Description
IdemixSignature(org.hyperledger.fabric.protos.idemix.Idemix.Signature proto)	Construct a new signature from a serialized IdemixSignature
IdemixSignature(IdemixCredential c, org.apache.milagro.amcl.FP256BN.BIG sk, IdemixPseudonym pseudonym, IdemixIssuerPublicKey ipk, boolean[] disclosure, byte[] msg, int rhIndex, org.hyperledger.fabric.protos.idemix.Idemix.CredentialRevocationInformation cri)	Create a new IdemixSignature by proving knowledge of a credential

Method Summary

Modifier and Type	Method	Description
org.hyperledger.fabric.protos.idemix.Idemix.Signature	toProto()	Convert this signature to a proto
boolean	verify(boolean[] disclosure, IdemixIssuerPublicKey ipk, byte[] msg, org.apache.milagro.amcl.FP256BN.BIG[] attributeValues, int rhIndex, java.security.PublicKey revPk, int epoch)	Verify this signature

Methods inherited from class java.lang.Object

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

Constructor Detail

IdemixSignature

public IdemixSignature(IdemixCredential c,
                       org.apache.milagro.amcl.FP256BN.BIG sk,
                       IdemixPseudonym pseudonym,
                       IdemixIssuerPublicKey ipk,
                       boolean[] disclosure,
                       byte[] msg,
                       int rhIndex,
                       org.hyperledger.fabric.protos.idemix.Idemix.CredentialRevocationInformation cri)

Create a new IdemixSignature by proving knowledge of a credential

Parameters:

c - the credential used to create an idemix signature

sk - the signer's secret key

pseudonym - a pseudonym of the signer

ipk - the issuer public key

disclosure - a bool-array that steers the disclosure of attributes

msg - the message to be signed

rhIndex - the index of the attribute that represents the revocation handle

cri - the credential revocation information that allows the signer to prove non-revocation

IdemixSignature

public IdemixSignature(org.hyperledger.fabric.protos.idemix.Idemix.Signature proto)

Construct a new signature from a serialized IdemixSignature

Parameters:

proto - a protobuf object representing an IdemixSignature

Method Detail

verify

public boolean verify(boolean[] disclosure,
                      IdemixIssuerPublicKey ipk,
                      byte[] msg,
                      org.apache.milagro.amcl.FP256BN.BIG[] attributeValues,
                      int rhIndex,
                      java.security.PublicKey revPk,
                      int epoch)
               throws CryptoException

Verify this signature

Parameters:

disclosure - an array indicating which attributes it expects to be disclosed

ipk - the issuer public key

msg - the message that should be signed in this signature

attributeValues - BIG array where attributeValues[i] contains the desired attribute value for the i-th attribute if its disclosed

rhIndex - index of the attribute that represents the revocation-handle

revPk - the long term public key used to authenticate CRIs

epoch - monotonically increasing counter representing a time window

Returns:

true iff valid

Throws:

CryptoException

toProto

public org.hyperledger.fabric.protos.idemix.Idemix.Signature toProto()

Convert this signature to a proto

Returns:

a protobuf object representing this IdemixSignature