Password

A password is a secret string used to authenticate a user to a computer system or service. It is typically combined with a username or account ID to prove identity during login. Passwords should be known only to the user and should be resistant to discovery by others.

Historically, simple passwords sufficed; as computing power increased, organizations adopted policies around length and complexity. Today, password storage emphasizes cryptographic hashing with a unique salt per password. Modern schemes like bcrypt, scrypt, and Argon2 are designed to be slow and memory-hard to deter brute-force attacks.

Security considerations: reuse across sites is risky; attackers can compromise multiple accounts if a password is reused. Users should enable multi-factor authentication when available. Password managers can generate and store long, unique passwords. Users should beware phishing and credential stuffing; systems should implement rate limiting and breach alerts.

Best practices for users: prefer long passphrases; avoid common words; consider a password manager; never share or write passwords; update compromised passwords promptly. For organizations: enforce minimum length, prohibit common passwords, monitor for leaks, and require MFA.

Trends: many services are moving toward passwordless authentication using hardware keys, biometrics, or WebAuthn. Even so, passwords remain widespread; understanding how they are stored and protected is essential for digital security.