计算机应用
計算機應用
계산궤응용
COMPUTER APPLICATION
2010年
2期
517-520
,共4页
奇异值分解%图像水印%伪验证
奇異值分解%圖像水印%偽驗證
기이치분해%도상수인%위험증
Single Value Decomposition (SVD)%image watermarking%fake verification
通过分析发现,一类基于奇异值分解的图像水印算法存在致命漏洞,即利用在水印嵌入过程中生成的密钥可以从其他图像(含未嵌入水印的图像)中提取出高相关的水印信息,称这一新发现的算法漏洞为水印算法的伪验证,并由此首次提出了水印算法伪验证的定义和判定条件.然后通过实例分析,指出基于奇异值分解的水印算法之所以存在伪验证,是由于奇异值分解使得水印信息主要包含于正交阵U、V中,因此水印的提取与正交阵U、V以及奇异值的分布类型有关,而与奇异值的具体取值无关.
通過分析髮現,一類基于奇異值分解的圖像水印算法存在緻命漏洞,即利用在水印嵌入過程中生成的密鑰可以從其他圖像(含未嵌入水印的圖像)中提取齣高相關的水印信息,稱這一新髮現的算法漏洞為水印算法的偽驗證,併由此首次提齣瞭水印算法偽驗證的定義和判定條件.然後通過實例分析,指齣基于奇異值分解的水印算法之所以存在偽驗證,是由于奇異值分解使得水印信息主要包含于正交陣U、V中,因此水印的提取與正交陣U、V以及奇異值的分佈類型有關,而與奇異值的具體取值無關.
통과분석발현,일류기우기이치분해적도상수인산법존재치명루동,즉이용재수인감입과정중생성적밀약가이종기타도상(함미감입수인적도상)중제취출고상관적수인신식,칭저일신발현적산법루동위수인산법적위험증,병유차수차제출료수인산법위험증적정의화판정조건.연후통과실례분석,지출기우기이치분해적수인산법지소이존재위험증,시유우기이치분해사득수인신식주요포함우정교진U、V중,인차수인적제취여정교진U、V이급기이치적분포류형유관,이여기이치적구체취치무관.
A fatal bug of a kind of Singular Value Decomposition (SVD)-based image watermarking was discovered in this paper. That is, using the same secret key which is produced in the embedding procedure, highly correlative watermark information can be extracted from other different images, even including non-watermarked images. This newly discovered bug was named as fake verification of watermark algorithm. At the same time, the definition and judging condition of fake verification were also presented. Then, the experimental results reveal that the watermark information is involved in the orthogonal matrix U, V after SVD. And the extracted watermark information is mainly involved in U, V, and the distribution of single value instead of exact single value. That is the reason why the SVD-based watermark algorithm has the bug of fake verification.
