Randomness Testing for Cyber Security

Randomness is crucial to enabling secure and robust communications, be it in key generation, authentication, or digital signatures. Using a weak random number generator will result in a weak cryptographic key which can lead to the leaking of sensitive information. Intuitively, a pseudorandom or random sequence should be ‘patternless’. A ‘truly random’ a sequence should arise from a natural physical phenomenon, such as an electronic circuit. However in cryptographic applications (i) a close approximation to a uniform distribution is also needed which is difficult to achieve reliably via physical generators;  We discuss how to test the strength of random number generators and use them to judge three pseudorandom bit generators; the AES block cipher (standard, strongly believed to be secure), the Dragon stream cipher (eStream finalist), and the GNU C library function rand(). We also test the output from a quantum random bit generator (QRBG). While the two ciphers can easily be distinguished from the much inferior rand(), the output statistics of the two classical generators are similar to that of the QRBG, and both provide high-quality pseudorandom bits.

We then briefly describe an insider threat detection framework which utilizes the attributed graph clustering techniques and outlier ranking mechanisms for enterprise users. This method is very effective, achieving the best area under ROC curve value of 0.7648.


Serdar Boztaş

Serdar Boztaş received the Bachelor’s degree from the Massachusetts Institute of Technology (MIT), and the M.S. and Ph.D. degrees from the University of Southern California, all in Electrical Engineering, in 1983, 1986 and 1990 respectively.

He was a Research Engineer at the Telecom Australia Research Laboratories in 1991–1992 and a Lecturer at Monash University during the years 1992–1995. Since 1996, he has been with first the Department of Mathematics and then the School of Mathematical and Geospatial Sciences, at RMIT University, Melbourne, Australia, first as Lecturer, then Senior Lecturer and since 2002 as Associate Professor of Information Security. He has co-founded in 2001 and is the Program Manager of the Master of Cyber Security program at RMIT. His research interests include coding theory, sequence design, information theory, information security, cryptography and combinatorics.

He gave invited lectures at the UNESCO-CIMPA summer school in Ankara, Turkey, on sequences over rings in 2009 and 2016, and was an invited plenary speaker at the 2013 IEEE Workshop on Signal Design and Applications, which took place in Tokyo, Japan. He has co-edited the proceedings of the 14th and 17th AAECC (Applied Algebra, Algebraic Algorithms and Error Correcting Codes) conferences in Melbourne and Bangalore, respectively. He was a co-organizer of the 2009 Workshop on Sequences Codes and Curves, in Antalya, Turkey, and was the General Chair of ACISP 2011, the 16th Australasian Conference on Information Security and Privacy, held in Melbourne, Australia. Most recently, he is organising an invited session on Entropy and its Applications, at the World Statistical Congress in Kuala Lumpur, which will take place in August 2019.

He has received total funding of more than $1.6 million, and directed multiple projects from the Australian Research Council and the Department of Defence on projects covering various aspects of Cyber Security and Network detection and fusion of information.