public class SPSXSIGSignatureScheme extends java.lang.Object implements MultiMessageStructurePreservingSignatureScheme, SPSMessageSpaceVerifier
SPSFSP2SignatureScheme,
the implementation can be used on its own, where it is secure under extended random message attacks [1].
[1] Abe et al.: Fully Structure-Preserving Signatures and Shrinking Commitments.
https://eprint.iacr.org/2015/076.pdf| Constructor and Description |
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SPSXSIGSignatureScheme(org.cryptimeleon.math.serialization.Representation repr) |
SPSXSIGSignatureScheme(SPSXSIGPublicParameters pp) |
| Modifier and Type | Method and Description |
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void |
doMessageChecks(PlainText plainText,
int expectedMessageLength,
org.cryptimeleon.math.structures.groups.Group expectedGroup)
Checks if the given plainText matches the structure expected by the scheme
and throws detailed exception if the plainText fails any check.
|
boolean |
equals(java.lang.Object o) |
SignatureKeyPair<SPSXSIGVerificationKey,SPSXSIGSigningKey> |
generateKeyPair(int numberOfMessages)
Generates a key pair for signing a block of
numberOfMessages messages
with each signature. |
int |
getMaxNumberOfBytesForMapToPlaintext()
Returns the maximal number of bytes that can be mapped injectively to a
PlainText by
SignatureScheme.mapToPlaintext(byte[], SigningKey) and SignatureScheme.mapToPlaintext(byte[], VerificationKey). |
SPSXSIGPublicParameters |
getPublicParameters() |
org.cryptimeleon.math.serialization.Representation |
getRepresentation() |
int |
hashCode() |
PlainText |
mapToPlaintext(byte[] bytes,
SigningKey sk)
Provides an injective mapping of the given bytes to a
PlainText usable with this scheme (which may be a
MessageBlock). |
PlainText |
mapToPlaintext(byte[] bytes,
VerificationKey pk)
Provides an injective mapping of the given bytes to a
PlainText usable with this scheme (which may be a
MessageBlock). |
PlainText |
restorePlainText(org.cryptimeleon.math.serialization.Representation repr) |
Signature |
restoreSignature(org.cryptimeleon.math.serialization.Representation repr) |
SigningKey |
restoreSigningKey(org.cryptimeleon.math.serialization.Representation repr) |
VerificationKey |
restoreVerificationKey(org.cryptimeleon.math.serialization.Representation repr) |
Signature |
sign(PlainText plainText,
SigningKey secretKey)
Signs the giving plaintext using the given signing key.
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java.lang.Boolean |
verify(PlainText plainText,
Signature signature,
VerificationKey publicKey)
Verifies the given signature for the given plaintext using the given verification key.
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clone, finalize, getClass, notify, notifyAll, toString, wait, wait, waitsign, sign, verify, verifygenerateKeyPairsign, sign, verify, verifyrestoreFromRepresentation, sign, verifypublic SPSXSIGSignatureScheme(SPSXSIGPublicParameters pp)
public SPSXSIGSignatureScheme(org.cryptimeleon.math.serialization.Representation repr)
public SPSXSIGPublicParameters getPublicParameters()
public SignatureKeyPair<SPSXSIGVerificationKey,SPSXSIGSigningKey> generateKeyPair(int numberOfMessages)
StandardMultiMessageSignatureSchemenumberOfMessages messages
with each signature.generateKeyPair in interface StandardMultiMessageSignatureSchemenumberOfMessages - the number of messages as input to sign supported by this key pairpublic Signature sign(PlainText plainText, SigningKey secretKey)
SignatureSchemesign in interface SignatureSchemeplainText - the message to signsecretKey - the secret signing keyplainText computed using secretKeypublic java.lang.Boolean verify(PlainText plainText, Signature signature, VerificationKey publicKey)
SignatureSchemeverify in interface SignatureSchemeplainText - the plaintext the signature should validate againstsignature - the signature to verifypublicKey - the verification key to verify withpublic void doMessageChecks(PlainText plainText, int expectedMessageLength, org.cryptimeleon.math.structures.groups.Group expectedGroup)
SPSMessageSpaceVerifier
For this default implementation, the following properties of the parameter plainText are checked:
* plainText is of type MessageBlock.
* The amount of PlainTexts matches expectedMessageLength.
* The elements stored in plainText are of type GroupElementPlainText.
* The elements stored in said GroupElementPlainTexts are \in expectedGroup
doMessageChecks in interface SPSMessageSpaceVerifierpublic PlainText restorePlainText(org.cryptimeleon.math.serialization.Representation repr)
restorePlainText in interface SignatureSchemepublic Signature restoreSignature(org.cryptimeleon.math.serialization.Representation repr)
restoreSignature in interface SignatureSchemepublic SigningKey restoreSigningKey(org.cryptimeleon.math.serialization.Representation repr)
restoreSigningKey in interface SignatureSchemepublic VerificationKey restoreVerificationKey(org.cryptimeleon.math.serialization.Representation repr)
restoreVerificationKey in interface SignatureSchemepublic PlainText mapToPlaintext(byte[] bytes, VerificationKey pk)
SignatureSchemePlainText usable with this scheme (which may be a
MessageBlock).
It only guarantees injectivity for arrays of the same length.
Applications that would like to use mapToPlaintext with multiple different array lengths
may want to devise a padding method and then only call mapToPlaintext with
byte arrays of the same (padded) length.
The contract is that VerificationKey pk and SigningKey sk are compatible
(in the sense that verify(m,sign(m, sk),pk) == true),
then mapToPlaintext(bytes, pk)) equals mapToPlaintext(bytes, sk) for all bytes.
mapToPlaintext in interface SignatureSchemebytes - bytes to be mapped to a PlainTextpk - the verification key for which the resulting PlainText should be valid
(note that the plaintext space may differ for different verification keys).public PlainText mapToPlaintext(byte[] bytes, SigningKey sk)
SignatureSchemePlainText usable with this scheme (which may be a
MessageBlock).
It only guarantees injectivity for arrays of the same length.
Applications that would like to use mapToPlaintext with multiple different array lengths
may want to devise a padding method and then only call mapToPlaintext with
byte arrays of the same (padded) length.
The contract is that VerificationKey pk and SigningKey sk are compatible
(in the sense that verify(m,sign(m, sk),pk) == true),
then mapToPlaintext(bytes, pk)) equals mapToPlaintext(bytes, sk) for all bytes.
mapToPlaintext in interface SignatureSchemebytes - bytes to be mapped to a PlainTextsk - the signing key for which the resulting PlainText should be valid
(note that the plaintext space may differ for different signing keys).public int getMaxNumberOfBytesForMapToPlaintext()
SignatureSchemePlainText by
SignatureScheme.mapToPlaintext(byte[], SigningKey) and SignatureScheme.mapToPlaintext(byte[], VerificationKey).
As described in SignatureScheme.mapToPlaintext(byte[], org.cryptimeleon.craco.sig.VerificationKey) there might be no injective PlainText for some byte arrays, e.g.
if the byte array is too long. Therefore, this method provides the maximal number of bytes that can be mapped
injectively to a PlainText.
getMaxNumberOfBytesForMapToPlaintext in interface SignatureSchemeSignatureScheme.mapToPlaintext(byte[], org.cryptimeleon.craco.sig.VerificationKey).public org.cryptimeleon.math.serialization.Representation getRepresentation()
getRepresentation in interface org.cryptimeleon.math.serialization.Representablepublic boolean equals(java.lang.Object o)
equals in class java.lang.Objectpublic int hashCode()
hashCode in class java.lang.Object