How MFA works
MFA combines factors from different categories: knowledge (a password or PIN), possession (an authenticator app, hardware key or phone), and inherence, meaning biometrics (a fingerprint or face scan). After the password is checked, the system prompts for a second factor before issuing a session.
Methods vary in strength. SMS codes are better than nothing but can be intercepted or SIM-swapped. Authenticator apps and push approvals are stronger, and phishing-resistant options such as FIDO2 security keys and passkeys bind the login to the real website, defeating most credential-phishing kits.
Why it matters for Canadian organizations
Stolen credentials remain a common cause of breaches, and MFA is among the most effective single controls against them. The Canadian Centre for Cyber Security recommends MFA for remote access and privileged accounts as a baseline measure.
Regulators and insurers increasingly expect it. PIPEDA requires safeguards appropriate to data sensitivity, OSFI B-13 expects strong authentication for technology access, and cyber insurance applications in Canada commonly ask whether MFA covers email, VPN and administrator accounts. Roll out in waves, beginning with your most privileged and most exposed users, to keep support demand manageable.
How to implement it
Prioritize administrator accounts, email, remote access and cloud applications first, then extend to all staff. Prefer phishing-resistant methods where possible, retire SMS for sensitive roles, and enable number matching or similar protections against push-fatigue attacks.
Plan the operational side as well. Provide secure account recovery, register backup factors, set conditional access rules by device and location, and monitor for repeated failed prompts, which can indicate an attacker working through stolen passwords. Document exceptions carefully, since every account without MFA is a likely target for credential attacks.
Frequently asked questions
Is MFA the same as two-factor authentication?
Two-factor authentication (2FA) is a type of MFA that uses exactly two factors. MFA is the broader term and can involve two or more. In everyday use the terms are often interchangeable. Both rely on at least one additional proof beyond a password.
Can MFA be bypassed?
Yes. Attackers use phishing proxies, push-notification fatigue, SIM swapping and stolen session tokens. MFA still blocks most password-only attacks, and phishing-resistant methods such as security keys close many of these gaps. Strong MFA, number matching and conditional access policies reduce these risks significantly.
Which MFA method is most secure?
Hardware security keys and passkeys based on FIDO2 are generally considered the strongest because they resist phishing. Authenticator apps rank next, with SMS and email codes being the weakest options. Choose the strongest method that your users and applications can support.
Related service: Identity and access management