What is SFA: Single-Factor Authentication

Single-factor authentication (SFA) means verifying a user’s identity with just one piece of information (one factor), most commonly a password or PIN. SFA stands for Single-Factor Authentication. You enter a password together with your username to sign in to an account or system. It is the simplest and most common sign-in method, but it can be the least secure if users do not follow basic password hygiene and handling practices. Its security depends mainly on password length and user discipline.

• If someone steals or guesses your password, they can sign in as you and access your data, email, and systems.
• Follow password best practices (long, complex, unique passwords stored in a password manager); with good hygiene, single-factor authentication can be reasonably safe for low-risk accounts.
• Many SMBs are adopting multi-factor authentication (MFA), which adds another verification step (such as an authenticator app code or security key) for stronger protection.

What single-factor authentication means for businesses

1. Employee onboarding

• With SFA, new hires usually get just a username and password for company systems, apps, or Wi‑Fi.
• HR or IT should deliver these credentials securely and document them properly.
• Risk: weak, reused, or leaked passwords let attackers get in quickly.

2.  Employee offboarding, revoking passwords and access

• Storing passwords in spreadsheets, notes, or on paper is a serious security risk.
• If accounts aren’t disabled when someone leaves, former employees might still sign in.
• Have a clear offboarding checklist: reset or revoke passwords and disable accounts immediately.

3. Tracking passwords and access 

• Keep an up-to-date inventory of who has access to each system and how each account is protected.

What are the pros and cons of single-factor authentication

Advantages of single-factor authentication

• Simplicity and convenience – users only remember a password, no extra apps or hardware tokens.
• Fast onboarding – IT/HR creates an account, shares the password → the employee can start right away.
• Low cost – no need for mobile authenticator apps, SMS gateways, or hardware security keys.

Risks of single-factor authentication

• Security relies solely on the password. Strong, unique passwords and good password hygiene reduce risk, but do not eliminate it.
• Human factor – in practice, people often reuse or write down passwords.
• Audits and accountability – it’s harder to prove who logged in, since knowing the password is enough.

How to use single-factor login securely

Username-and-password sign-in can be sufficient for small and midsize businesses if clear policies are enforced:

1. Strong passwords and enforced password policy (complexity, rotation/change cadence, etc.)
2. Employee security awareness training
3. Password disablement or reset during offboarding
4. Ability to centrally change or reset user passwords
5. Additional protection for the company network from external threats (for example, private cloud or VPN)