منابع مشابه
study of hash functions based on chaotic maps
توابع درهم نقش بسیار مهم در سیستم های رمزنگاری و پروتکل های امنیتی دارند. در سیستم های رمزنگاری برای دستیابی به احراز درستی و اصالت داده دو روش مورد استفاده قرار می گیرند که عبارتند از توابع رمزنگاری کلیددار و توابع درهم ساز. توابع درهم ساز، توابعی هستند که هر متن با طول دلخواه را به دنباله ای با طول ثابت تبدیل می کنند. از جمله پرکاربردترین و معروف ترین توابع درهم می توان توابع درهم ساز md4, md...
Watermarking Scheme Based on Multiple Chaotic Maps
a watermarking scheme for Grayscale image isproposed based on a family of the chaotic maps and discretecosine transform. Jacobian Elliptic mapis employed to encrypt ofwatermarked logo. Piecewise nonlinear chaotic map is also usedto determine the location of DCT coefficients for the watermarkembedding. The purpose of this algorithm is to improve theshortcoming of watermarking such as small key s...
متن کاملA Note on Spectrum Preserving Additive Maps on C*-Algebras
Mathieu and Ruddy proved that if be a unital spectral isometry from a unital C*-algebra Aonto a unital type I C*-algebra B whose primitive ideal space is Hausdorff and totallydisconnected, then is Jordan isomorphism. The aim of this note is to show that if be asurjective spectrum preserving additive map, then is a Jordan isomorphism without the extraassumption totally disconnected.
متن کاملA Note on Quadratic Maps for Hilbert Space Operators
In this paper, we introduce the notion of sesquilinear map on Β(H) . Based on this notion, we define the quadratic map, which is the generalization of positive linear map. With the help of this concept, we prove several well-known equality and inequality...
متن کاملA Note on Open Maps
In [l ] E. E. Floyd proved that if X and Y are Peano continua and f: X—>F is light, open, and onto, then the covering homotopy property for a point holds. Here we will prove (Theorem 1) that under different (roughly speaking, more general) conditions the covering homotopy property for a point holds up to a homotopy. This has certain implications on the induced homomorphism of the fundamental gr...
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ژورنال
عنوان ژورنال: Applied Mathematics Letters
سال: 1989
ISSN: 0893-9659
DOI: 10.1016/0893-9659(89)90126-2