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What is two-factor authentication and how does it work?

What is 2FA?

Users supply two distinct authentication factors as part of a security procedure known as two-factor authentication (2FA), also known as two-step verification or multi-factor authentication.

A user's credentials and the resources they can access are both better protected with the implementation of 2FA. When compared to authentication techniques that rely on single-factor authentication (SFA), where the user supplies only one element, usually a password or passcode, two-factor authentication offers a better level of security. In order to employ two-factor authentication, a user must supply a password as the first factor and another, distinct element, typically a security token or a biometric factor like a fingerprint or facial scan.

By making it more difficult for attackers to access a person's devices or online accounts, two-factor authentication adds an extra layer of security to the authentication process. This is because, even if the victim's password is compromised, a password alone will not be enough to pass the authentication check.

The use of two-factor authentication to restrict access to confidential systems and data is not new. Online service providers are increasingly utilizing 2FA to prevent hackers from using user credentials after they have stolen a password database or obtained them through phishing scams.

What are authentication factors?

Factors for 2FA

A person can be verified in a variety of ways utilizing multiple authentication techniques. The majority of authentication techniques currently in use rely on knowledge factors, such as a conventional password, while two-factor authentication techniques also include either a possession element or an inheritance factor.

Following is a list of authentication factors in a roughly chronological sequence of computing adoption:

  • A knowledge factor is anything the user is aware of, such as a shared secret, a password, or a personal identification number (PIN).

  • When approving authentication requests, a possession factor is something the user possesses, such as an ID card, a security token, a telephone, a mobile device, or a smartphone app.

  • The user's physical self possesses a biometric element, also referred to as an inherence factor. These could be physical traits matched to personal traits, such as fingerprints verified by a fingerprint reader. Behavioral biometrics, such as keystroke dynamics, gait, or speech patterns, as well as facial and voice recognition, are additional inherence elements that are frequently exploited.

  • The location from which an authentication attempt is being made typically indicates a location factor. This can be enforced by restricting authentication attempts to particular devices in a specific location or by tracing the geographic origin of an authentication attempt using the source Internet Protocol address or other geolocation data, such as Global Positioning System (GPS) data, derived from the user's mobile phone or other devices.

  • A time factor limits access to the system outside of that timeframe and limits user authentication to a certain time window during which logging on is allowed.

How does two-factor authentication work?

2FA Process Img

Depending on the application or vendor, different two-factor authentication options may be available. However, the general, multi-step procedure for two-factor authentication is the same:

  • The program or the website asks the user to log in. Users enter what they are aware of, often their username and password. The server for the website then discovers a match and recognizes the user.

  • The website generates a special security key for the user for procedures where passwords are not necessary. The key is processed by the authentication mechanism, and it is verified by the website's server.

  • The user is then prompted to start the second login stage by the website. The user must demonstrate that they own something only they would possess, such as biometrics, a security token, an ID card, a smartphone, or another mobile device, however, this step can take a variety of forms. This is the possession of an inherited factor.

  • A one-time code generated in step four could then need to be entered by the user.

  • The user is authenticated and given access to the application or website after supplying both factors.

Future of authentication

Three-factor authentication, which often requires possession of a physical token and a password used in conjunction with biometric data, such as fingerprint scans or voiceprints, may be of use in environments that demand stronger security. In order to decide whether a user should be authorized or prohibited, variables including geolocation, device type, and time of day are also taken into consideration. A user's keystroke length, typing speed, and mouse movements can also be covertly observed in real time as behavioral biometric identifiers to offer ongoing authentication rather than a single one-off authentication check during login.

Even though it's ubiquitous, using passwords as the primary authentication mechanism no longer always provides the security or user experience that businesses and their customers want. Additionally, even if legacy security products like password managers and multi-factor authentication (MFA) make an effort to address the issues with usernames and passwords, they rely on a system that is fundamentally out-of-date: the password database. As a result, a lot of businesses are using passwordless authentication. Users can safely authenticate themselves in their applications without having to enter passwords by using techniques like biometrics and secure protocols. Employees may now access their work without having to enter a password at work, and IT still has complete control over each login. As an alternative to conventional authentication techniques, the use of blockchain is also gaining popularity, for instance through decentralized identification or self-sovereign identity.

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