Decrypt given data previously encoded with cast5-ecb cipher algo. CAST5 in ECB (Electronic Codebook) mode, where each block is encrypted independently, making it fast but less secure. CAST5 was introduced in the 1990s as an updated version of the CAST cipher, including ECB as one of its modes. CAST5-ECB is insecure due to the potential for repeating patterns in the ciphertext, and it is not recommended for use. 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.