Convert hash code to String

Hashing is a form of 'one way' encryption and it's not generally possible to recover what has been hashed from the hashcode.

Moreover, a given hashcode will not be unique and will correspond to multiple strings. It is easy to see that this is the case because an int (which the GetHashcode method produces) can only have around 4 billion possible values. Remembering that strings can in theory have up to 2 billion characters, there are certainly far more possible strings than there are unique ints.