I need to decrypt an rc4 encrypted mobile number in query parameter and send it back to target system.

[biranchibarik50]

I need to decrypt an rc4 encrypted private data comes in query parameter and send it back to target system.

[dchiesa1]

If I were doing this I would probably use an RC4 implementation in JavaScript.

Here's one. Just embed that into a JS callout , and you're done. (you may need to base64 encode/decode as well)

The simplicity of rc4 is what is so attractive. Encryption and decryption are reflexive, so you use the same function to encrypt and to decrypt. But there are known vulnerabilities in RC4, so it is not recommended. Don't use it, if possible!