John the Ripper is an Open$-$Source password security auditing and password recovery tool

available for many operating systems. It is one of the most popular password testing and

breaking programs. JtR autodetects the encryption on the hashed data and compares it

against a large plain$-$text file that contains popular passwords, hashing each password, and

then stopping it when it finds a match. JtR also includes its own wordlists of common

passwords for $20+$ languages. These wordlists provide JtR with thousands of possible

passwords from which it can generate the corresponding hash values to make a high$-$value

guess of the target password. Since most people choose easy$-$to$-$remember passwords, JtR is

often highly effective even with its out$-$of$-$the$-$box wordlists of passwords.