Software diversity

From HandWiki

Software diversity is a research field about the comprehension and engineering of diversity in the context of software.


The different areas of software diversity are discussed in surveys on diversity for fault-tolerance[1] or for security.[2][3]

The main areas are:


Code transformations

It is possible to amplify software diversity through automated transformation processes that create synthetic diversity. A "multicompiler" is compiler embedding a diversification engine.[5] A multi-variant execution environment (MVEE) is responsible for selecting the variant to execute and compare the output.[6]

Fred Cohen was among the very early promoters of such an approach. He proposed a series of rewriting and code reordering transformations that aim at producing massive quantities of different versions of operating systems functions.[7] These ideas have been developed over the years and have led to the construction of integrated obfuscation schemes to protect key functions in large software systems.[8]

Another approach to increase software diversity of protection consists in adding randomness in certain core processes, such as memory loading. Randomness implies that all versions of the same program run differently from each other, which in turn creates a diversity of program behaviors. This idea was initially proposed and experimented by Stephanie Forrest and her colleagues.[9]

Recent work on automatic software diversity explores different forms of program transformations that slightly vary the behavior of programs. The goal is to evolve one program into a population of diverse programs that all provide similar services to users, but with a different code.[10] This diversity of code enhances the protection of users against one single attack that could crash all programs at the same time.

Transformation operators include:[11]

  • code layout randomization: reorder functions in code
  • globals layout randomization: reorder and pad globals
  • stack variable randomization: reorder variables in each stack frame
  • heap layout randomization

Natural software diversity

It is known that some functionalities are available in multiple interchangeable implementations. This natural diversity can be exploited, for example it has been shown valuable to increase security in cloud systems.[12]


  1. Deswarte, Y.; Kanoun, K.; Laprie, J.-C. (July 1998). "Diversity against accidental and deliberate faults" (in en-US). Proceedings Computer Security, Dependability, and Assurance: From Needs to Solutions (Cat. No.98EX358). IEEE Comput. Soc. pp. 171–181. doi:10.1109/csda.1998.798364. ISBN 978-0769503370. 
  2. Knight, John C. (2011), "Diversity" (in en), Dependable and Historic Computing, Lecture Notes in Computer Science, 6875, Springer Berlin Heidelberg, pp. 298–312, doi:10.1007/978-3-642-24541-1_23, ISBN 9783642245404 
  3. Just, James E.; Cornwell, Mark (2004-10-29). "Review and analysis of synthetic diversity for breaking monocultures". Proceedings of the 2004 ACM workshop on Rapid malcode. ACM. pp. 23–32. doi:10.1145/1029618.1029623. ISBN 978-1581139709. 
  4. Schaefer, Ina; Rabiser, Rick; Clarke, Dave; Bettini, Lorenzo; Benavides, David; Botterweck, Goetz; Pathak, Animesh; Trujillo, Salvador et al. (2012-07-28). "Software diversity: state of the art and perspectives" (in en). International Journal on Software Tools for Technology Transfer 14 (5): 477–495. doi:10.1007/s10009-012-0253-y. ISSN 1433-2779. 
  5. "Protecting Applications with Automated Software Diversity". 2018-09-10. 
  6. Coppens, Bart; De Sutter, Bjorn; Volckaert, Stijn (2018-03-01), "Multi-variant execution environments", The Continuing Arms Race: Code-Reuse Attacks and Defenses (ACM): pp. 211–258, doi:10.1145/3129743.3129752, ISBN 9781970001839 
  7. Cohen, Frederick B. (1993). "Operating system protection through program evolution". Computers & Security 12 (6): 565–584. doi:10.1016/0167-4048(93)90054-9. ISSN 0167-4048. 
  8. Chenxi Wang; Davidson, J.; Hill, J.; Knight, J. (2001). "Protection of software-based survivability mechanisms" (in en-US). Proceedings International Conference on Dependable Systems and Networks. IEEE Comput. Soc. pp. 193–202. doi:10.1109/dsn.2001.941405. ISBN 978-0769511016. 
  9. Forrest, S.; Somayaji, A.; Ackley, D.H. (1997). "Building diverse computer systems" (in en-US). Proceedings. The Sixth Workshop on Hot Topics in Operating Systems (Cat. No.97TB100133). IEEE Comput. Soc. Press. pp. 67–72. doi:10.1109/hotos.1997.595185. ISBN 978-0818678349. 
  10. Schulte, Eric; Fry, Zachary P.; Fast, Ethan; Weimer, Westley; Forrest, Stephanie (2013-07-28). "Software mutational robustness" (in en). Genetic Programming and Evolvable Machines 15 (3): 281–312. doi:10.1007/s10710-013-9195-8. ISSN 1389-2576. 
  11. "Automated Software Diversity: Sometimes More Isn't Merrier". 2018-09-10. 
  12. Gorbenko, Anatoliy; Kharchenko, Vyacheslav; Tarasyuk, Olga; Romanovsky, Alexander (2011), Using Diversity in Cloud-Based Deployment Environment to Avoid Intrusions, Lecture Notes in Computer Science, 6968, Berlin, Heidelberg: Springer Berlin Heidelberg, pp. 145–155, doi:10.1007/978-3-642-24124-6_14, ISBN 978-3-642-24123-9