| Summary: | 碩士 === 東海大學 === 資訊工程學系 === 101 === In recent years, the Advanced Encryption Standard (AES) and Data Encryption Standard (DES) have been commonly and widely used to protect important information carried in electronic documents. However, due to the quick development of parallel computing techniques and hardware speed, the two algorithms have so far faced the threats of Brute-Force attacks. To defend against this type of threats, in this study, we proposed a new data encryption approach, called the Secure Feedback Encryption Method (SeFEM for short), which employs three security schemes, including a sequential-logic style encryption/decryption mechanism, three-dimensional operation and dynamic transition box, to effectively enhance the security level of the delivered ciphertext, and increase the difficulty of cracking the encryption keys so as to well protect encrypted data from Brute-force and cryptanalysis attacks. The sequential-logic style encryption/decryption mechanism is a feedback process in which each of its calculation iteration/step generates three internally used dynamic feedback keys for the next iteration/step. The three-dimensional operation, including exclusive-or (⊕), binary addition (+2) and exclusive-and (⊙) operators, is utilized to further increase the computational complexity of the encryption process. The dynamic transition box nonlinearly rearranges the bits of a key for each operation, so as to increase the difficulty of cracking the SeFEM. The analytical results show that the SeFEM has a higher security level, encryption efficiency and usage flexibility than the DES and AES have.
|
|---|
