# Tag Info

2

Suffix salt If you add the salt after the message, $\operatorname{MD5}(m \mathbin\| salt)$, that doesn't prevent Alice from finding two collisions. Example; Consider that if the message $m$ of Alice is an exact multiple of the block size of the $\operatorname{MD5}(m \mathbin\| salt)$ then your signature will be vulnerable to hash chosen-prefix collisions. ...

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$2^{64-1}$ bits that make 2.30584301 exabytes *. If you are not restricted to SHA256, then use SHA512 that allows files to have size at most $2^{128}-1$, or use SHA3 that has no limit. The NIST must use a limit due to the artifact of the MD construction. SHA256 is standardized in 2001 along with SHA512. They have internal block size 512 and 1024 respectively,...

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The size is just restricted by a length encoding at the end of the last block that is hashed using SHA-256 - one of the two main hash functions that make up the SHA-2 family. If you extend that size then you'd have your secure hash function with extended input. However, there is an easier way. The SHA-512 hash function - the other main hash function in the ...

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Given an infinite number of repetitions of the above, is it possible that all possible hashes will be computed an infinite number of times? Yes, it is possible; however it is (to the best of our knowledge) extremely unlikely. Not only would MD5 (on 16 byte inputs) be a permutation, it would also need to be a single cycle permutation. Is it possible that ...

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