Encrypt given data using rc2-cfb cipher algo. RC2 in CFB (Cipher Feedback) mode, turning the block cipher into a stream cipher with feedback. CFB mode was used with RC2 to provide better encryption for data streams, though it still had vulnerabilities. RC2-CFB suffers from the inherent weaknesses of the RC2 algorithm and should not be used for secure communications. Our encryption process prepends the IV string used during the encryption process in the encrypted data so that it can be used during decryption.