Encrypt given data using camellia-256-ecb cipher algo. Camellia in 256-bit key size with ECB mode, encrypting each block independently without chaining. ECB is a simple mode but considered insecure for many applications due to the potential for pattern leakage in ciphertext. While Camellia is secure, ECB mode is insecure and should be avoided for most use cases due to its vulnerability to block repetition attacks. Our encryption process prepends the IV string used during the encryption process in the encrypted data so that it can be used during decryption.