SMS 2-factor authentication and OTP

Two-factor authentication (2FA) is a security process that requires users to provide two forms of authentication before accessing a protected resource.

One-time password (OTP) is a form of 2FA that provides a unique, time-sensitive code that is generated and sent to the user, typically via SMS.

Using SMS for 2FA and OTP provides an additional layer of security to protect against unauthorized access to sensitive information or transactions. Here's how it works:

  1. User attempts to log in to an account or access a protected resource.

  2. The system sends an OTP code to the user's mobile phone via SMS.

  3. The user enters the OTP code in the login form or on the protected resource page.

  4. The system verifies the OTP code and, if it's valid, grants access to the protected resource.

SMS 2FA and OTP is an effective way to increase security because the code is sent to the user's mobile phone, which is typically only accessible by the user, making it difficult for unauthorized users to access protected resources. Additionally, OTP codes are time-sensitive, providing an additional layer of security by requiring users to enter the code within a specific time window.

SMS 2FA and OTP is commonly used for financial transactions, such as online banking and credit card purchases, as well as for accessing sensitive information, such as email accounts and other online services.