摘要
由带Hash的ElGamal加密与Schnorr签名构成的加密方案尽管从直观上看是抗选择密文攻击的,但以前的证明中或者需要在线知识提取假设,或者只能在更受限制的GenericGroup模型中得以证明,因此,其严格的归约化证明仍然是一个公开问题.作者在Gap Diffie-Hellman(GDH)假设下,在Random Oracle模型中,利用了Random Oracle Hash函数的特点模仿解密而严格证明了该方案确实达到了这个强安全级别.
The encryption constructed by combing the Hashed ElGamal encryption and Schnorr signature looks like secure against chosen ciphertext attack, but its security is still not formally proved despite some attempts are made , among which some needs the non standard on llne knowledge extractor assumption and some another needs the more restricted Generic Group Model. Here, for the first time , the authors give a reductionist proof that the scheme is really achieving this strong secure level under the standard Gap Diffie-Hellman（GDH） assumption in the Random Oracle Model. The reason the authors could achieving this proof is that we construct the decryption simulator utilizing the property of Random Oracle Hash property and avoid the previously used knowledge extractor.
出处
《四川大学学报（自然科学版）》
CAS
CSCD
北大核心
2006年第1期71-77,共7页
Journal of Sichuan University(Natural Science Edition)
基金
国家自然科学基金(60302015)
信息安全国家重点实验室2004年第1批开放课题(01-01)
