Is cracking MD5 hash a form of P VS NP problem?

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I have a question,Is cracking MD5 hash a form of P VS NP problem?

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No, because finding a preimage of a MD5 hash (which I assume is what you mean by "cracking" it) is a problem with a fixed, unchangeable input size, namely 128 bits.

P versus NP is about how well the best possible algorithm for a problem scales when the size of the input goes towards infinity. A problem with a limited input size does not allow that question to be asked at all.

Knowing that P$\ne$NP would tell us nothing about how fast an algorithm for finding MD5 preimages would be.

Knowing that P$=$NP wouldn't really tell us anything. It would imply that there's a polynomial-time algorithm that takes a description of a hash function (assuming the forward algorithm for the hash is not uselessly slow) and a hash, and produces a preimage. But it would not tell anything about the degree of that polynomial, or how large its constant factors are. So the polynomial algorithm might still not be practically feasible in the "128 bits" case.