How two-factor authentication works
After entering a password, the user must supply a second factor from a different category. This might be a time-based code from an authenticator app, a push approval, a hardware security key or a biometric check.
An attacker who steals or guesses the password still cannot log in without the second factor. Strength varies: SMS codes can be intercepted or redirected, while hardware keys and passkeys resist phishing far better. Attackers have adapted by tricking users into approving prompts or entering codes on fake login pages, so the type of second factor chosen makes a measurable difference in real protection.
Why it matters for Canadian organizations
Stolen and reused credentials are among the most common ways attackers enter organizations. 2FA blocks many of these attempts and is a basic expectation in cyber insurance questionnaires and security audits.
The Canadian Centre for Cyber Security recommends multi-factor authentication for remote access, email and administrator accounts. Applying it also supports the safeguards expected under PIPEDA, Law 25 and OSFI technology risk guidance. Many cyber insurance applications now ask directly whether it is enforced for email and remote access, and lacking it can lead to higher premiums or declined coverage.
How to implement it
Start with the highest-risk accounts: administrators, email, remote access, VPN and cloud consoles. Prefer authenticator apps or hardware keys over SMS, and use phishing-resistant options for privileged users.
Provide backup recovery methods, train staff to reject unexpected push prompts, and monitor for repeated denied requests, a sign of prompt-bombing attacks. Extend coverage to all users and applications over time. Include contractors and service accounts in your plan, review exceptions regularly, and communicate clearly to staff why it is required, which improves adoption and reduces help desk calls.
Frequently asked questions
Is 2FA the same as MFA?
Two-factor authentication is a type of multi-factor authentication that uses exactly two factors. MFA is the broader term and can include more than two. In everyday use, people often treat the terms as interchangeable. Both terms are widely used in practice.
Is SMS two-factor authentication secure?
It is better than a password alone, but weaker than other options. SMS codes can be intercepted through SIM swapping or phishing. Authenticator apps and hardware security keys are safer, particularly for administrators and sensitive accounts. Prefer stronger options for sensitive accounts.
Can 2FA be bypassed?
Yes, in some cases. Attackers use phishing proxies, stolen session tokens or push-fatigue attacks to get around weaker methods. Phishing-resistant factors such as FIDO2 security keys and passkeys significantly reduce these risks. Review your options carefully before choosing.
Related service: Identity and access management