OTP Message

In the SMS OTP authentication method, a one time password (OTP) is sent with the SMS text to the user's phone.

OTP, or One-Time Password, SMS is a short message containing a one-time auto-generated password that is sent to the registered mobile phone number of the user who has initiated the request. This technology is perhaps the most popular mechanism used by companies around the world to make sure that the login request has been generated by an authorized person. It is very simple to use the OTP SMS service.

As soon as a user enters their username and password to log in, OTP SMS is sent on their mobile phones. This SMS contains a code, usually four to six digits and valid for only one-time use, and the users are required to enter this code as quickly as possible (in most cases, the OTP expires within a minute and the user has to generate a new one) into the given space in order to proceed with the login. This way, it is ensured that the person, logging into his/her account is authorized by the account holder, to gain access to it.

Google encourages its Gmail customers to use the two-step OTP verification provided by the service on their email account to prevent unauthorized access to it. The OTP service is both fast and free to use. As soon as users log in to their Gmail account from an unauthorized device, an OTP SMS is sent to their mobile phone which users need to enter in order to access their account. According to Google, it is very easy for account passwords to be stolen, hence OTP is necessary to protect against such incidents.