Friday, 26 October 2007
Hashing is a superb way of validating and in some way to find out if someone has tempered with your files. But the chances are that if he can tamper with your files that he could change the table of hashes. So how to find out if someone has really done something bad to your computer. My idea is that you can create a hash with a password. So to hash a file you have to enter a password this is incorporated into the hash. So only if the file has not changed and the password was right the hash will be the same. But now this will return (c2471b27e6a1410c1e51814a5a7011a3ee8692af) a normal human being can not remember this. So why not map this hash to a dictionary. So i have a file (listofimportantfiles) I hash this with my password then I map this to a dictionary and the program returns 'tree'. I can easily remember tree as the correct hash but not c247.... Of course to be 100% correct you would need a dictionary as big ass all hash combinations. I notice that this is impossible (+- 24^65) With a sufficient big dictionary the chances are quite small.