Multi-factor authentication (MFA)

wikipedia:Multi-factor authentication (MFA) is a method of computer access control which a user can pass by successfully presenting several separate authentication stages through credentials based on knowledge (something you know), possession (something you have), and inherence (something you are), in other words, it is a system that requires more than one method of authentication from a self-reliant listing of credentials to verify a user's identity for login.

Examples

• Bank card + PIN number
• One-time password (OTP) tokens
• Certificates
• Smart cards

2FA Mobile applications

Different 2FA open-source mobile app are available such us :

• FreeOTP (2013, Android, iOS): free and open-source

Android: Download from Google Play[1] or F-Droid[2] iOS: Download from the App Store[3]

• AndOTP (Android): free and open-source

Android: Download from Google Play[5] or F-Droid[6]

• Google Authenticator (2010, Android, iOS): free, was open-source until 2013
• Microsoft Authenticator (2016)
• MobileID, deepnet security
• Authy
• Cisco Duo Mobile
• LinOTP

Activities

• Read https://www.digitalocean.com/community/tutorials/how-to-set-up-multi-factor-authentication-for-ssh-on-ubuntu-16-04 (OATH-TOTP)
• Read wikipedia:Help:Two-factor_authentication

See also

• VPN: IPsec (Openswan), OpenVPN, Forticlient, GlobalProtect (PAN-OS), WireGuard (Linux Kernel), Tailscale, PulseSecure, WebVPN, SoftEther, ESP, IKE, AWS VPN, Zerotier, VPN client, Pritunl, GCP Cloud VPN
• MFA: FreeOTP, Google Authenticator, Okta Verify, Duo Security, Microsoft Authenticator, Strong customer authentication, Dualshield, HOTP, TOTP, OATH, Authy, Push authentication, google-authenticator, Duo Mobile, DenyAllExceptListedIfNoMFA, Configure MFA on AWS, LastPass Authenticator mobile app
• AAA: Authc, Authz, Password policy, OAuth, OpenID, OIDC, LDAP, RADIUS, TACACS+, XTACACS, SAML, Secure LDAP, IEEE 802.1X, CHAP, RBAC, MFA, SCIM, Amazon Cognito

https://lwn.net/Articles/581086/