Ravi Sir's Cards › AWS
OTP notifier with SNS
What is a VPC: your own private network inside one AWS Region, example ThreeTierVpc 10.0.0.0/16.
Read card text
What this card says
Why do we need it?
UPI and banking apps send a one-time password for a minute of trust. You must expire it and not store it in plain text.
What is it?
POST /otp/request creates a 6-digit code, stores sha256(dest:otp) + expiresAt in DynamoDB, publishes via SNS. POST /otp/verify checks the hash.
How to do it
Table PK dest, SNS email topic (prefer email in class), Lambda Put/Get + Publish, routes request and verify.
SMS_MODE off
Example
curl request to you@example.com → email has 6 digits → curl verify returns {"ok":true}.