[Fun]/prog/ Challenge #-1764 [CompSci]

How many iterations of the MD5 algorithm, performed on the hash emitted by the previous hashing, and using an arbitrary initial string, would be needed for the sum to begin to loop over past values?

Prizes:
Participation ribbon: Worst case time.
Bronze plaque: Best case time.
Silver trophy: Average time.
Gold statue: Proof of all of the above.
1000 tons of Platinum: Find an input that will loop in under 100K iterations.
Sussman's head in a jar of formaldehyde: Find an input that will loop in only 100 iteration.
A ticket to Gensokyo and a free Touhou: Find an input that will loop in only 2 iterations.

>>169
I tried to fix some things and got banned. Just leave things as they are.

>>171
Nobody needs you bump threads, especially non-programming ones, you fucking idiot. Just kill yourself.

oh nice, now we have a rampant moderator who deletes everything, may be even with a script
king log is better than king heron, you know, see aesop's fables

>>173
calm down dude, if the thread is already at the top it doesn't matter if i use sage or not

>>173
sure moderator-san, let's leave threads from 2007 on the front page!

moderator-san is wise, and is certainly not suffering from autism, i will dispatch myself swiftly

>>173
Cool your jets, pops

Best case: 2 iterations
Worst case: 2^128 + 1 iterations
Average case: No idea, but probably close to worst case, since MD5 is designed to have a low possibility of hash collisions.

>>171
suck my anus

>>1
interesting. note that after n iterations, there are (n^2-n)/2 different possible sums.

>>178
no you suck my anus, ``faggot''

This basically boils down to finding a collision between an input and a valid hash, correct?

>>180
no, dumbshit

>>1
I found an input that will loop in just zero iterations!

>>182
define zero

>>183
your IQ

>>180
idiot