Encrypt given data using cast-cbc cipher algo. CAST in CBC (Cipher Block Chaining) mode, where each plaintext block is XOR'd with the previous ciphertext block before encryption. CAST, a block cipher developed in the 1990s, was designed for high performance and security, with CBC mode being one of the earliest block cipher modes. CAST-CBC is considered secure, but it is less commonly used compared to modern ciphers like AES. Our encryption process prepends the IV string used during the encryption process in the encrypted data so that it can be used during decryption.