A memorized secret is a password or passphrase that a user must remember and type during login. It is the most common form of authentication, but it is also one of the weakest when it is short, predictable, reused, or shared. Security frameworks treat memorized secrets as only one factor of identity, not proof of trust by themselves.
In cyber security, memorized secrets matter because attackers often target them first. Guessable passwords, password spraying, and credential stuffing can turn a single bad secret into broad account access, especially when the account has privileged permissions. Defenders reduce that risk with long passphrases, password screening against known-bad choices, rate limiting, login monitoring, and multi-factor authentication. The example of a weak administrator password shows why a memorized secret can be the first point of failure in a much larger breach.