I need to test the decryption module in my API, how can I send encrypted payloads from postman to validate this? I need to encrypt it using a public key - self signed.
Hi @Portugal1,
Welcome to the Postman Community! 
You should be able to do this encryption, however it depends on the cipher you are using to encrypt. Out of the box, postman supports crypto-js nodejs library that can be used in a pre-request script to encrypt your payload with your public key. However, I am not sure what cipher you need, which may not be available.
If you are curious about other libraries supported out of the box, check out their documentation here:
https://learning.postman.com/docs/postman/scripts/postman-sandbox-api-reference
Hope this helps!
Regards,
Orest