对J.von zur Gathen和I.E.Shparlinski提出的有限域上乘法噪音多项式插值算法进行了分析,提出了改进算法.利用L.Babai最近向量格归约算法得到更精确的估计向量,再计算出插值多项式的倍数多项式的系数,从而计算出原插值多项式的系数.改进算法降低了原算法中有限域阶的下界,对较小阶有限域上的多项式也可以进行乘法噪音插值.
To realize delegation between different users in a mixed cryptosystem,a proxy signature scheme for ID-based original signers and certificated-based proxy signers（PSS-ID-CER）is defined.Using the bilinear properties of the pairings and the characters of key generations of certificate-based cryptosystems and ID-based cryptosystems,a construction for such a scheme is also presented.To prove the security of the proposed scheme,a general security model for this scheme under adaptive chosen-PKG,chosen-ID,chosen-delegation,chosen-ProxySigner-public-key,chosen-proxy-key and chosen-message attack is defined.The proposed scheme is provably secure under the random oracle model and the hardness assumption of computational Diffie-Hellman problem.
