# Tag Info

5

What are the advantages/disadvantages of this approach instead of using traditional hash functions, such as MD5 and SHA-1? Those are not precisely alternative approaches. MD5 and SHA-1 use Davies-Meyer construction with certain block ciphers that do not see much use on their own (SHACAL has seen some). So in a way you are already doing that if you use MD5 ...

11

The disadvantage of this approach is that block ciphers are not necessarily designed with this goal in mind. Specifically, AES has related-key problems, and DES completely breaks in Davies-Meyer. In general, block ciphers are not necessarily ideal ciphers and should be used as intended which is as pseudorandom permutations. In contrast, SHA256 and the like ...

0

Matyas–Meyer–Oseas one-way compression method is a cryptographic algorithm based in block ciphers. The difference is that the subkeys of each round are calculated differently unlike normal block ciphers were you specify the key before data encryption. It can be seen as a special MAC algorithm. The advantages of this algorithm compared to SHA-1 are ...

4

Surprisingly enough, it would appear that generating a simultaneous collision wouldn't be that much more expensive than generating a single collision for SHA-1. The basic idea is to form a $2^{64}$ wide multicollision on SHA-1; that is, $2^{64}$ distinct messages that all SHA-1 hash to the same value. We can do this by using Joux's idea of forming finding ...

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