Performance Comparison Between AES256-Blowfish and Blowfish-AES256 Combinations

Security level is an essential feature of a cryptographic algorithm. Performing two well known cryptographic algorithms may improve a possibility to gain higher security level. This research implements a composite cryptosystem, which consists of AES256 and Blowfish algorithms. In combining AES256 and Blowfish, two options are available. The first option executes the AES256 followed by Blowfish (AES256-Blowfish). The second option is performing Blowfish and followed by AES256 (Blowfish-AES256). Security level in this research is measured by the required time to decrypt the ciphertext. Longer decryption time lead to a longer time to perform a brute force attack to get the original text message, therefore more secure. Experiment result shows that a composite cryptosystem on AES256-Blowfish required longer decryption time compare to the composite cryptosystem in reverse order (Blowfish-AES256).