07-09-2019, 05:49 PM
(07-09-2019, 04:54 PM)DanielG Wrote: Wow what a weird hash, this will have a lot of collisions since the value of every letter is just raised to the 5th power and added, so the order of the letters does not matter (so you will most likely find more than one string). The string "abc" has the same hash as "cba" and "bac" etc...
This is also just some basic addition so making a brute forcer in C and running it on all your CPU cores would already be really fast. You might want to try that before making a GPU variant.
Also if you look at the 'hash' you can also make a guess to the length range of the input. For example assuming standard ascii string input (letters, numbers, special chars) and a hash of 335544320, then if you divide it by 122^5 (letter z) and 32^5 (space) you will see the string length is most likely between 1 and 10 long.
(07-09-2019, 04:54 PM)undeath Wrote: If you implement your own module you can use hashcat for this. btw, that's a bloody stupid hash function.
Thanks for your replies, I know it's a very simple hashing function, I don't need to find a particular string, just one which fits a given hash, so collisions are fine. Your length guessing trick doesn't seem to be working for high numbers like this one for example: 396018663018502 (the one I have is very similar (same number of digits)), division by 122^5 gives 14652.6609277 and by 32^5 gives 11802275.8668, it's because the function has overflows. Anyway I'll try to implement a C brute forcer running on all my CPU cores as you advised and if it's not enough I'll look into hashcat modules.