Examples are taken from security advisories and from unpublished loopholes in the author's own work. Widely-known passwords Imagine that you choose a password to protect your systems and then advertise that password in big neon signs for all to see. That would not be a very responsible thing to do. Surprisingly, this is almost exactly what some programs have been doing for a long time.
Passwords are the traditional method to authenticate users to computer systems.
Murphy's law and computer security. Venema, Wietse. 1996. Murphy's law and computer security.