complexities of attacks on MD5 and SHA-1
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Taken from the SLOTH paper, the current estimated complexities of the best known attacks against MD5 and SHA-1:
| Common-prefix collision | Chosen-prefix collision | |
| MD5 | 2^16 | 2^39 |
| SHA-1 | 2^61 | 2^77 |
| MD5|SHA-1 | 2^67 | 2^77 |
MD5|SHA-1 is a concatenation of the outputs of both hashes on the same input. It is a technique aimed at reducing the efficiency of these attacks, but as you can see it, it is not that efficient.
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