If I use john for getting weak passwords in ex.: 2010, then can I use the john.pot file later or there could be situations when the hash is the same, but the passwords differ?
Can the ~/.john/john.pot file be used forever?
password
Of course, you can use your old john.pot file.Because password hashes of current systems are usually additionally secured by salting and the used hash algorithms are quite strong, is improbable that you find a hash collision. But in the unlikely case, that you find one, both password should work on the target system.