- Undeniable signature
Undeniable signatures are a form of
digital signature invented byDavid Chaum andHans van Antwerpen in1989 . They have two distinctive features,# The verification process is interactive, so that the signatory can limit who can verify the signature.
# A disavowal protocol, which is acryptographic protocol that allows them to determine whether a given signature is aforgery .The first means that a signatory can allow only others who are authorized to access the document to verify their signature. If the document were to be leaked to a third party, the third party would be unable to verify that the signature is genuine.
However, because of this property it means that the signatory may deny a signature which "was" valid. To prevent this, there is the second property, a method to prove that a given signature is a forgery.
See also
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Topics in cryptography References
*David Chaum, Hans van Antwerpen: "Undeniable Signatures"; Crypto'89, LNCS 435, Springer-Verlag, Berlin 1990, 212-216.
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