Two-factor authentication (2FA) is a security mechanism that requires two different factors to verify a user’s identity: typically, something the user knows (a password) and something the user has (a temporary code, device, or application).
Common types of 2FA
- codes sent via SMS,
- authentication apps generating time-based codes,
- physical security keys.
Value and limitations
2FA significantly reduces the risk of unauthorised access when:
- it is configured by the legitimate account owner,
- recovery mechanisms are properly managed.
However, it is not infallible: if an attacker gains prior access to an account and enables 2FA under their own control, this mechanism can become a lockout tool against the original owner.
Conclusion
2FA is an essential security measure, but its effectiveness depends as much on who controls its configuration as on the technology itself.
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