La double authentication or two-factor authentication (2FA) is a security method that requires two distinct types of identification to access an account, an application or a system.
Two-factor authentication (2FA) is a security measure that strengthens the protection of online accounts by requiring two distinct forms of identification before granting access. This method adds an extra layer of security beyond the simple password, making it much more difficult for unauthorised people to access sensitive information.
It's a strong authentication because it is based on the principle of multi-factorisation: instead of a single identification element (such as a password), the user must provide at least two proofs of identity from three categories.
👉 Types of authentication factors
Users must provide at least two proofs of identity from three categories.
The three main types of authentication factor are :
- Something you know information that only you should know → password, PIN code, secret question (place of birth, pet name, etc.)
- Something you own : a physical object that only you should have → smartphone (SMS code, authentication app such as Google Authenticator, physical security key, smart card...)
- Something you are (biometrics) : a unique physical characteristic → fingerprint, facial recognition, voice recognition, retinal or iris scan...
Examples
- Connecting to an e-mail account : Once you have entered your password, you will receive a code by text message on your phone, which you must enter to complete the connection.
- Access to a banking application : In addition to your login and password, the application may require biometric authentication (fingerprint or facial recognition).
- Connecting to a corporate network (VPN) : use of a physical security key to validate access.
How dual authentication works
The 2FA process is generally as follows:
- The user enters their username and password (first factor).
- The system checks this information and, if it is correct, requests a second authentication factor.
- The user supplies the second factor, which can be :
- A temporary code sent by SMS or generated by an application
- Fingerprint or facial recognition
- A physical token like a YubiKey
- The system checks this second factor and grants access if everything is correct.
📈 Trends
- Growing adoption The 2FA adoption rate has risen from 28% in 2017 to 78% in 2021 among businesses (source: Zippia)..
- Biometrics on the rise The use of biometric data (fingerprints on phones) as a second factor is gaining in popularity.
- Authentication without password trend towards authentication methods that do away with passwords altogether.
- Continuous authentication constant verification of the user's identity throughout the session.
Advantages of 2FA
- Enhanced security : Dual authentication makes unauthorised access much more difficult, even if a hacker manages to obtain your password.
- Protection against phishing : even if you fall victim to a phishing attempt and disclose your password on a fake site, the hacker will not be able to access your account without the second authentication factor.
- Reducing the risk of identity theft : By protecting access to your accounts, 2FA helps prevent theft of your personal information.
- Protection against brute force attacks : These attacks involve trying out a large number of password combinations. The 2FA makes these attacks ineffective.
- Regulatory compliance : In some sectors, 2FA is a regulatory requirement to protect sensitive data.
It is important to note that although 2FA greatly improves security, it is not infallible. More advanced methods, such as multi-factor authentication (MFA), which uses more than two factors, can offer even more robust security for the most sensitive systems.
