Verifiably encrypted signature scheme with extended properties
LI Jun-ling · Journal of PLA University of Science and Technology · 2012
Verifiably encrypted signature schemes can be used to construct the fair exchange protocols in e-commerce.To protect the sensitive messages(say,secret business contract) to be exchanged in the fair exchange protocols,in this paper,based on the signature proposed by Boneh,the Diffie-Hellman key exchange principle and the techniques of symmetric encryption,a verifiably encrypted signature scheme,which can protect the sensitive messages,was constructed.The scheme has the properties as follows:(1) It inherits the properties of an ordinary verifiably encrypted signature scheme;(2) Anyone(including the adjudicator) but the signer or the designed verifier knows nothing about what message(say,the context of a contract) is signed;(3) In case of adjudication,the adjudicator cannot obtain the signer's basic signature(say,the signed contract).However,with the help of the adjudicator T,the designed verifier can gain the basic signature;(4) When some secret information is released,the message included in the verifiably encrypted signature can be publicly verified.This public verifiability can help the authority(say,a judge) make a judge in case of dispute.The scheme proves to be secure under the hardness assumption of Discrete Logarithm Problem(DLP) and q-Strong Diffie-Hellman Problem(q-SDHP).