One Time Password
By: Thenusan Santhirakumar
Tags: Security, Identity, Otp Verification, Authentication, Time Synchronization

One Time Password

When we try to do a crucial task in a software-based system, we may sometimes face giving a valid mobile phone number or email address to make the task to be successful. The particular application will send us a random password in numbers or letters or mixed of both through the given communication medium. The password is needed to be correctly entered back to the application by the user. Sometimes they may send token embedded links also to be verified. The one-time password(OTP) is also known as dynamic password.

Photo by Markus Spiske on Unsplash

An OTP (One-Time Password) is a dynamically generated numeric or alphanumeric string of characters that is used to authenticate and verify users before a transaction or a session in an app or website. OTP reduces fraud access for applications through the traditional username password-based authentication. Fraud attempts to catch the OTP is comparatively lower as OTP is valid for a particular time period.

One time passwords must be generated using high secure algorithms that must not be catchable or guessable by any kind of attackers. Several approaches are being used to create one time passwords.

Simple methods such as transaction numbers can provide a way to create one-time passwords using simple algorithms. Using an algorithm to generate a new password based on the previous password. Using an algorithm where the new password is based on challenge-response mechanisms. Each new OTP may be created from the previously used OTPs.

OPT delivery

After an OTP is created, it must be received by the particular user through a secure way. Generally, OTPs are sent to the users via SMS services, call services or emails. In recent times, the token embedded access links are also sent to a verified user device to be clicked for being authenticated. For example, The Medium is currently using the magic link authentication mechanism to verify its users.

OTP as a service

OTP is used by industries to raise data security and prevent attacks on the business. There are many vendors give OTP as a software service. Developers may simply use their APIs into the systems. Those APIs are easy to use and integrate as a black box in software systems. An OTP service provider guarantees timely delivery of OTPs to the right customers via SMSes and voice calls to the registered email or phone number.

Two types of OTP delivering services

SMS OTP Service Voice OTP Service

Businesses use cases of OTP verification service

Two-factor authentication: Implementing a further layer of security in software systems without adding more complexity.

Transaction authentication: Retain all transactions secure. Add a layer of security with OTP verification to ensure safe transactions.

Passwordless logins: Clients can be verified using an OTP every time they log in to the software system.

Password Resets: Instead of sending codes or links via email, use the OTP service to authenticate users before password resets.

Account Reactivations: Reactivate a user account with a confirmed acceptance from them. Using OTP verification as a means of verifying identity.

Spam prevention: Expertly control spam registrations, and avoid fake signups. Optimize and secure systems against spam attacks.

Simple OTP Generation using Random in-built library in Python

Sample OTP Generation using python

The above code for simple OTP generator will give you a basic idea of how random can be used to generate an OTP. Algorithms should be created according to the requirements of the particular use case such as security concern, usability, simplicity and etc.

I believe that you understood the topic discussed today. If you have any concerns or any clarifications, don’t hesitate to contact me through the response section. Thank you for spending your precious time to read this article.

Cheers….

Photo by Hanny Naibaho on Unsplash

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