Decrypt given data previously encoded with sm4-ctr cipher algo. SM4 in CTR (Counter) mode, using a counter value to generate a keystream for encryption. CTR mode was introduced for SM4 to enhance performance and parallel processing capabilities. SM4-CTR is highly secure and efficient for encryption in both hardware and software environments. 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.