I'm trying to find a string that shares the same hash result as a given string.
For Example:
If I have the String 'den' and use Java's hashcode() method the hash result = 99,341
String s = "den";
System.out.println(s.hashCode());
Result = 99,341
Knowing that the hashcode() method computes
s[0]*31^(n-1) + s[1]*31^(n-2) + ... + 2[n-1]
How would I go about taking this result (99,341) and finding a string (of the same length) as 'den' with the equivalent hash value?
You need to solve this equation:
(x * 31^(3-1)) + (y * 31^(3-2)) + (z * 31^(3-3)) = 99341
It's a plane, every point in that plane is good for you as long as x,y,z are integers and between 0 and 255 (if you are only talking about ASCII).
One possible solution is x=100, y=101, z=110.
To simply find another one, you can just change the order of two of them and see what would be the third one, e.g.:
x=101
y=???
z=110
(101 * 31^(3-1)) + (y * 31^(3-2)) + (110 * 31^(3-3)) = 99341
where y=70 (F) so eFn should have the same hashCode as den using the function in your question.