Some Results on Unicity of Entire Functions Related to Normal Families

IntroductionLet D be a domain in C.Define for f mero-morphic on D and a,b∈C,we putE(a,f)={z∶f(z)-a=0}where a zero of multiplicity m is counted m times inthe set.And put-E(a,f)=f-1({a})∩D={z∈D∶f(z)=a}Then f and g share a IM(ignoring multiplicities),i.e.-E(a,f)=-E(a,g)If f-a and g-a have the same zeros with thesame multiplicities,then f and g share the value aCM(counting multiplicities),i.e.E(a,f)=E(a,g)A meromorphic function f on C is called anormal function if there exists a posit…     

视频哈希的安全性分析

为了对鲁棒多媒体哈希的安全性进行定量分析,用Shannon的唯一解距离来解释鲁棒多媒体哈希的安全性.以一个典型的鲁棒视频哈希算法为例,对该算法的特征提取方式进行数学建模,并针对不同的攻击类型,用Shannon的唯一解距离测量该鲁棒视频哈希算法的安全级别,定量分析其安全性.分析结果表明:鲁棒视频哈希算法一个密钥的重复使用次数不能超过所求得的唯一解距离,否则,算法的密钥可以被估计出来.