Decrypt given data previously encoded with rc4-hmac-md5 cipher algo. RC4 used with HMAC-MD5, combining the RC4 stream cipher with the MD5 hash function for message authentication. RC4-HMAC-MD5 was used in some legacy systems but is now deprecated due to vulnerabilities in both RC4 and MD5. RC4-HMAC-MD5 is insecure and should not be used due to weaknesses in both components of the algorithm. Our decryption process assumes the IV string is prepended in the encoded string during the encryption process. You can not decrypt and get the correct results if the IV or passphrase mismatch occurs between encryption and decryption process.