We discuss two intrinsic weaknesses of the spectral graph partitioning method, both of which have practical consequences. The first is that spectral embeddings tend to hide the best cuts from the commonly used hyperplane rounding method. Rather than cleaning up the resulting suboptimal cuts with local search, we recommend the adoption of flow-based rounding. The second weakness is that for many...

HAS-V is a cryptographic hash function which processes 1024-bit message blocks and produces a hash value of variable length. The design of the hash function is based on design principles of the MD4 family. Recently, weaknesses have been shown in members of this family. Therefore, the analysis of the HAS-V hash function is of great interest. To the best of our knowledge this is the first article...

TriStrata appears to have implemented a variation of Maurer’s randomised cipher. We define a variation of Maurer’s cipher that appears to be similar to the TriStrata version, and show several cryptanalytical attacks against our variant.

We show that for various choices of the parameters in the SL2(IF2n) hashing scheme, suggested by Tillich and Zémor, messages can be modified without changing the hash value. Moreover, examples of hash functions “with a trapdoor” within this family are given. Due to these weaknesses one should impose at least certain restrictions on the allowed parameter values when using the SL2(IF2n) hashing s...

b a c k g r o u n d  &  aim:   assessment  could  be  assumed  as  a  valuable  mean  of  highlighting  the organization  strengths and spotting its weaknesses.  academies  are not exceptions  in this regard. knowing the items, which entail more concentrated  attention, the leadership  of the academy will shift the resources to compensate the extenuations. this study aimed to provide the iran a...