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OTP (One Time Password or Pin) login is quite popular in most programming languages. However, you need to make it secure by following practices:
- Limit Login Attempts – Limit login attempts to 3 to 5
- Block Over Attempts – If more than 10 attempts in the last 24 hours, block user/IP
- Expire Time – Expire OTP in 2 to 5 minutes
- OTP RESET – RESET OTP after once validated (success login)
You can change these numbers based on your application requirement.