Klapper, Andrew*

Design of FCSR Based Stream Ciphers in Software

Project description - A stream cipher is a symmetric key cipher that operates with a time-varying transformation on individual plaintext digits. Stream ciphers are used where large amounts of data must be encrypted, such as downloads of JPEG files to video on demand and voice over IP. A pseudo-random sequence called a keystream is generated by a finite state automaton. The keystream is combined with the plaintext to obtain the cipher text. Speed is essential in the design of stream ciphers. In software systems we want to exploit operations that are built into the system architecture, so we focus on word based designs. Feedback with carry shift register (FCSRs) are building blocks for such automata that Dr. Klapper co-invented and has been studying since 1992. The structure of an FCSR is determined by a connection integer. The key goal of this project is to find connection integers that lead to keystreams with long period and good statistical properties. This involves searching for integers with critical properties and testing properties of the resulting keystreams. Code will be written in the C programming language. The time for generating keystream will be recorded for later comparison. This study will result in improved design of FCSR based stream ciphers. It will from part of Ting Gu's PhD dissertation.

Status of project
Below is a table that lists batch jobs we have submitted. All of them are completed.

Job_Id Status Wall-time
111576 Completed 00:32:31 of 30:00:00:00
111589 Completed 00:43:55 of 30:00:00:00
111575 Completed 00:33:04 of 30:00:00:00
111588 Completed 00:44:09 of 30:00:00:00

Project participants:

Dr. Andrew Klapper (advisor)
Ting Gu (Graduate student)

Software module:

Python
gcc