Encrypt given data using cast cipher algo. CAST is a family of symmetric block ciphers with variable key sizes, designed as a fast and secure encryption method. CAST was developed in the 1990s by Carlisle Adams and Stafford Tavares and has been used in various security protocols. CAST is considered secure but not as widely used as AES or Camellia in modern cryptographic applications. Our encryption process prepends the IV string used during the encryption process in the encrypted data so that it can be used during decryption.