RT-OCFB: Real-Time Based Optimized Cipher Feedback Mode

Abstract

Several modes of operation have been built upon block cipher security. Among them, CFB is considered to be one of the popular modes of operation because of its self-synchronizing property. Besides, appearance of OCFB makes CFB even more competitive. However, because of the stalling problem (i.e., there is a need to stall while doing block encryption) and the inability to arrange the keystream in advance, both the CFB and OCFB modes are considered to be inadequate for such real-time applications, where the appearance of inputs is expected to be uniform. In this article, researchers present a new mode of operation based on the underlying foundation of both the CFB and OCFB modes of operation, called real-time based optimized cipher feedback mode (RT-OCFB), which remedies this problem. They also argue that the proposed mode of operation (RT- OCFB) holds the similar imperative security properties as CFB and OCFB, which are indeed essential for modern cryptography.

Keywords:

• block cipher
• CFB
• keystream
• OCFB
• real-time
• self-synchronization
• stalling

Acknowledgements

The authors would like thank the editor and the anonymous referee for their valuable comments.

Additional information

Notes on contributors

Tzonelih Hwang

Tzonelih Hwang received MS and PhD degrees in Computer Science from the University of Southwestern Louisiana in 1988. He is currently a distinguished professor in the Department of Computer Science and Information Engineering, National Cheng Kung University (NCKU), Tainan, Taiwan. Dr. Hwang has actively participated in several research activities, including as a research scientist at the Center for Advanced Computer Studies, University of Southwestern Louisiana. He is also a vigorous member of the editorial board of some reputable international journals. He has published more than 250 technical papers and holds five patents. His research interests include network and information security, access control systems, error control codes, security in mobile communication, and quantum cryptography.

Prosanta Gope

Prosanta Gope received his MTech degree in Computer Science and Engineering from National Institute of Technology (NIT), Durgapur, India, in 2009. He has been pursuing his PhD degree in Computer Science and Information Engineering, National Cheng Kung University (NCKU), Tainan, Taiwan. His research interests include authentication, authenticated encryption, access control systems, security in mobile communication, and cloud computing.