“Sometimes administrators set up fake user accounts (“honeypot accounts”) so that an alarm can be raised when an adversary who has solved for a password for such an account by inverting a hash from a stolen password file then attempts to login,” they said.
Accordingly, they recommend adding multiple fake passwords to every user account and creating a system that allows only the valid password to work and that alerts administrators whenever someone attempts to use a honeyword. “This approach is not terribly deep, but it should be quite effective, as it puts the adversary at risk of being detected with every attempted login using a password obtained by brute-force solving a hashed password,” they said.
On the other hand, if numerous attempted logins are made using honeywords, or if honeyword login attempts are made to admin accounts, then it’s more likely that the password database has been stolen. But as numerous breaches continue to demonstrate, regardless of the security that businesses have put in place, they often fail to detect when users’ passwords have been compromised. But that approach is insecure, and password-security experts have long recommended that businesses use built-for-purpose password hashing algorithms such as bcrypt, scrypt or PBKDF2, which if properly implemented are much more resistant to brute-force attacks.
That’s why an early warning system such as the use of honeywords might buy breached businesses valuable time to expire passwords after a successful attack, before attackers have time to put the stolen information to use.