Step-by-Step Guide to Implementing User-Specific Rate Limiting for OTP Logins

In today’s digital landscape, security is paramount, especially when it comes to online logins. One of the most common methods for secure authentication is the One-Time Password (OTP) system, which generates a unique password for each login session. However, OTP-based logins are susceptible to brute force attacks - when unauthorized users attempt to guess the password through trial and error. A crucial way to enhance your security is by implementing user-specific rate limiting. In this guide, we will take you through the process step by step, ensuring you have the tools and knowledge you need to successfully strengthen your login security.

Why Use User-Specific Rate Limiting?

Traditional security measures often involve limiting login attempts based on the user's IP address. While this can work in certain situations, it may lead to issues in environments where multiple users share the same IP, such as in offices or public networks. By implementing user-specific rate limiting, you limit login attempts based on individual user accounts or devices. This approach significantly reduces the risk of brute force attacks while allowing legitimate users to access their accounts without unnecessary lockouts.

Tools Needed

1. Cloudflare Rate Limiting Cloudflare is a website security service that helps protect your site from various online threats, including brute force attacks. It offers an easy way to configure rate limiting based on user requests.

   
   

2. AWS API Gateway

   Amazon Web Services (AWS) API Gateway allows you to create and manage APIs. It provides features that let you control user access and limit the number of requests per user.

   
   

Step-by-Step Implementation Guide

Step 1: Set Up a Unique User Account System

First and foremost, ensure that your application requires users to create unique accounts. A solid account system will involve:

• User Registration: Allow users to sign up with their details and create a unique password.

  
  

• Login Process: Ensure users must log in with their credentials

  
  

Step 2: Register for a Cloudflare or AWS Account

To use either Cloudflare or AWS, the first step is to create an account.

• Creating a Cloudflare Account:

  1. Go to Cloudflare.

     
     

     

  2. Click on the "Sign Up" button.
     

     
     

     

     
     

  3. After sign up, login into your Cloudflare account

     
     

     

     
     

  4. Dashboard Page after login

     
     
     
     

     

     
     

  5. Click on "Add a domain" to setup the website

     
     

     

     
     

  6. Input your website domain to proceed with the setup

     
     

     

     
     

  7. Now, to activate your website on Cloudflare, update the nameserver record given by Cloudflare to your domain registrar

     
     

     

     
     

• Creating an AWS Account:

  1. Sign up for AWS

     
     

     

     
     

  2. Signup for AWS

     
     

     

     
     

  3. Log in to the Cloudflare dashboard ↗, and select your account and zone.

     
     

Step 3: Configure Rate Limiting

For Cloudflare:

1. Log in to your Cloudflare dashboard.

2. Select the website you want to protect.

3. Go to Security > WAF > Rate limiting rules

4. To create a new empty rule, select Create rule

   
   

   

   
   

5. Now, on the "Rate limiting rules" page, configure the rate limiting configuration.

   

   
   

6. Configure your rule to limit requests made by user accounts. For example, set a limit of 100 requests per minute for each user account, and add a rule such as: add an API path expression for the rule.

7. Add a rule condition such as "No of requests and period when the rate would exceed".

8. Add action, such as what to do when the rule matches for that duration.

9. Now click on "Deploy" to create the rate-limiting rule.

   
   

For AWS API Gateway:

1. Log in to the AWS Management Console.

   
   

   

   
   

2. Select API Gateway from the services list.

   
   

   

   
   

3. Choose to create a new API or select an existing one

   
   

   

   
   

4. Navigate to "Usage Plans" and create a new plan. Set your limits for requests, such as allowing a maximum of 5 requests per user per minute.

   
   

   

   
   

5. Implement API keys that correspond to individual users to help track usage.

   
   

   

   
   
   
   

Step 4: Implement Exponential Backoff

Next, configure exponential backoff in your application. This method increases the waiting time between successive failed login attempts. For example:

• After the 1st failed attempt: Wait for 1 minute.

• After the 2nd failed attempt: Wait for 2 minutes.

• After the 3rd failed attempt: Wait for 4 minutes, and so on.

This strategy discourages repeated unauthorized attempts while allowing legitimate users to recover their access.

Step 5: Add CAPTCHA

To further secure your login process, integrate a CAPTCHA feature that prompts users to confirm they are human after a certain number of failed attempts. Here’s how to do it:

1. Choose a CAPTCHA service, such as Google reCAPTCHA.

2. Sign up for an API key on their platform.

3. Follow the integration instructions provided by the CAPTCHA service to add the CAPTCHA to your login form - it usually involves adding a small code snippet.

   
   

Step 6: Monitor and Adjust

Once implemented, regularly monitor login activities:

• Check for any unusual patterns, such as repeated failed attempts.

• Adjust your rate limits and CAPTCHA settings as necessary to balance user experience with security.

  
  

Conclusion

In today's digital world, securing users' login information is crucial. Implementing user-specific rate limiting for OTP logins defends against brute force attacks, protecting sensitive data and your application's integrity.

Tools like Cloudflare and AWS API Gateway simplify enforcing rate limits and enhance security. By creating a unique user account system, setting rate limits, implementing exponential backoff, and adding CAPTCHA challenges, you establish layers of security to protect users.

Monitoring login activities helps you respond to threats while maintaining a positive user experience. Investing in these measures fosters user trust and solidifies your reputation as a secure platform.

Keep security practices updated and informed about vulnerabilities to offer a safe and seamless user experience, allowing confident engagement with your application.