Reversing an integer hash function

I&#x27;m collecting such inverters at <a href="https:&#x2F;&#x2F;github.com&#x2F;rurban&#x2F;smhasher&#x2F;tree&#x2F;inverse&#x2F;inverse" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;rurban&#x2F;smhasher&#x2F;tree&#x2F;inverse&#x2F;inverse</a><p>But only 3 so far.

Is there a category of hash functions that hash a 64&#x2F;32 bit input to exactly 64&#x2F;32 bits output, such that all inputs are uniquely preserved? This could be an interesting property for a hash table of integers, because a hash match implies a key match.

&gt; otherwise you could simply trace backwards and generate an input that produces a specific hash<p>This is when I know for sure that I&#x27;m not included in that &quot;you&quot;.

Excellent tutorial for bitwise arithmetic this is. The key is the motivation you receive from the prospect of being able to do something that seems &quot;l33t&quot;.