3eee 1.0 Password Recovery Contest

This is the first encryption tool I've analyzed. This program can encrypt and decrypt files with one password, the password could be as long as you want. So i've studied the algo and here'r my results:

CyptedByte( i ) = OriginalByte( i ) XOR Password( h )
h = i MOD LenghtPassword
i = i+1
loop until i = FileLenght

So it's just a simple xor! This encryption is not so bad, cause if we only have an encrypted file, it would not be so easily to recover the file's password, but it's possible.In crypto we have to study the algo from variuos points of view, let's say that the cracker knows somethings about the file and the password, this algo presents lots of problems:

1)If you know the password lenght then the password can be forced in a couple of hours
2)If you have the some bytes of the original file and their location in the file you can recover some chars of the password (if not all)[the first password's lenght bytes of original file are enought to recover the password in one second]
3)If you have the whole original file the password is recovered immidiately.
4)If you know some bytes of the password and it's lenght you can recover L/PL*NC bytes (where L=file's lenght, PL=password's lenght and NC=number of know chars of the password)
5)It's possible to recover the password's lenght cryptoanalyzing the encrypted file

Due all this presented I think that this program has a bad encryption algorithm.

Program's Url

Unknown