What is multi-factor authentication (MFA) and why should it be enforced for cloud accounts?

MFA requires two or more verification factors: something you know (password) + something you have (TOTP app, hardware key) + something you are (biometric). Even if a password is compromised, MFA prevents unauthorized access.

For AWS/cloud accounts:

• Enforce MFA on the root account immediately and don’t use it routinely
• Require MFA for IAM users via SCP or IAM policy condition
• Use hardware MFA keys (YubiKey) for privileged accounts
• Enable AWS Organizations SCPs to deny API calls unless MFA is present