Authentication

“Trust, but verify.” — In digital systems, never trust; always verify. That is authentication.

Most modern authentication relies on one or more of these three categories of "factors": authentication

(lowest to highest):

The user holds a private key; the server knows the public key. The server issues a challenge; the user signs it with the private key. : SSH keys, WebAuthn (passkeys). Phishing-resistant because the private key never leaves the device and the challenge is bound to the origin. “Trust, but verify

Authentication is generally categorized into three main "factors." The more factors used, the more secure the authentication process is considered to be. but verify.” — In digital systems