This is less frightening than a real photo of me

Stephen Drape

I'm a Post Doctoral Research Fellow working with Professor Clark Thomborson and a member of the Secure Systems Group. I moved to New Zealand from Yorkshire in January 2006.

Research interests

My main area of interest is Software Security for the protection of intellectual property. I am particularly interested in applying formal methods such as Refinement, Software Specification, Abstract Data-Types and Functional Programming to obfuscation and watermarking.

In my DPhil(*) thesis I considered obfuscating abstract data-type and regarded obfuscation as data-refinement. I modelled the data-type operations using the functional language Haskell and I generalised the array split obfuscation. A particular benefit of this approach is the ability to produce random obfuscations so that different program executions give rise to different obfuscations making the programs particular obscure. Another benefit was the ability to prove correctness and derive obfuscated operations from unobfuscated ones.

(*) Oxford speak for PhD.

Teaching

I am not currently teaching any courses at the moment. However, at the University of Oxford, I demonstrated practicals for courses on Functional Programming, Procedural Programming and Compilers and I taught the MSc classes for Software Specification and Design Using Z. Plus, I spent 5 years at a secondary school teaching Maths and IT for GCSE and A-Level.

I am currently a co-supervisor for Anirban Majumdar. We're working on techniques for using program slicing to design obfuscations.

Publications and Resources

"Specifying Imperative Data Obfuscations" by Stephen Drape, Clark Thomborson and Anirban Majumdar. Accepted for the 10th Information Security Conference (ISC'07). Valparaiso, Chile, October 2007. Draft PDF.
"Metrics-based Evaluation of Slicing Obfuscations" by Anirban Majumdar, Stephen Drape and Clark Thomborson. Accepted for the 2007 International Workshop on Data Hiding for Information and Multimedia Security in conjunction with IAS'07 (Third International Symposium on Information Assurance and Security). Manchester, UK, August 2007. Draft PDF.
"Slicing Aided Design of Obfuscating Transforms" by Stephen Drape, Anirban Majumdar and Clark Thomborson. Accepted for the IEEE/ACIS Conference (ICIS 2007). Melbourne, Australia, July 11-13 2007. Draft PDF.
"Design and Evaluation of Slicing Obfuscations" by Stephen Drape and Anirban Majumdar. CDMTCS Technical Report 311, June 2007. Link to PDF.
"The Suitability of Different Binary Tree Obfuscations" by Stephen Drape. CDMTCS Technical Report 310, June 2007. Link to PDF.
"Generalising the Array Split Obfuscation" by Stephen Drape in Information Sciences, Volume 177, Issue no 1, pages 202-219, January 2007. DOI link.
"A Survey of Control-Flow Obfuscations" by Anirban Majumdar, Clark Thomborson and Stephen Drape, to appear in ICISS 2006, Kolkata, India 2006. Published by Springer Berlin / Heidelberg in Information Systems Security, Volume 4332, pages 353-356. DOI link.
"An Obfuscation for Binary Trees" by Stephen Drape - To appear in TENCON 2006, Hong Kong. Draft version (pdf). Slides for the talk (PDF).
"Obfuscation of Abstract Data Types" by Stephen Drape - DPhil Thesis, The University of Oxford, Trinity Term 2004 (Supervisor: Jeff Sanders). PDF.
"Using Haskell to Model Tree Obfuscations" by Stephen Drape - OUCL PRG Technical Report, August 2004 - available here as PS and PDF version.
"The Matrix Obfuscated" by Stephen Drape - OUCL PRG Technical Report, June 2004 - available here as PS and PDF version.
"Obfuscating Set Representations" by Stephen Drape - OUCL PRG Technical Report, May 2004 - available here as PS and PDF version.
"Transforming the .NET Intermediate Language Using Path Logic Programming" by Stephen Drape, Oege de Moor and Ganesh Sittampalam in Principles and Practice of Declarative Programming (PPDP, Pittsburgh, USA, October 2002), pages 133-144, ACM Press, 2002. (Link to PDF)
"Functional Cryptography" by Stephen Drape - MSc dissertation, The University of Oxford, 2001 (Supervisor: Richard Brent) PDF.

A draft of an article on developing notation for watermarking is available here pdf.

Sample pages from the first volume of Problem Pages. The first and second volume are available from the Mathematical Association. The first volume "Problem Pages" was edited by Charlie Stripp and Steve Drape. The second volume "Problem Pages 11-16" was edited by Steve Drape and Barbara Cullingworth.

Other activities

2006 - 2007 Reviewer for SAC'07 (ACM Symposium on Applied Computing), Journal of Systems and Software published by Elsevier and IET Software.
2006 Chair for the "Programming Languages & Software Engineering" session at TENCON 2006, Hong Kong.
2005 Presented a poster session with Patrick Lynch (The University of Hull) at ALT-C 2005, Manchester. Posters in pdf.
2005 Gave a talk at the ieUS conference in Syros, Greece, August 2005. (slides).
2004 Participated in the One Day Workshop in Refactoring Functional Programs at the University of Kent (slides).
2002 - 2004 Graduate Representative for the Programming Research Group, Oxford University Computing Laboratory. Duties involved liasing with academic and administrative staff to raise various graduate student issues.
1995 - 2005 Member of the Mathematical Association Post-16 education sub-committee. Secretary of the committee for 3 years. Editor of two volumes of Maths teacher resources called "Problem Pages". Chair of the Problem Pages subcommittee.

Biography

1991-1994 BA in Mathematics at St John's College, University of Oxford.
1994-1995 PGCE in Mathematics at The University of Hull.
1995-2000 Secondary School Teacher at Cottingham High School, East Yorkshire. Taught GCSE Maths and IT and A-Level Maths, Further Maths and Computing. Assistant Head of Year for 2 years and a form tutor for 5 years.
1999 MA from St John's College, University of Oxford.
2000-2001 MSc in Computer Science at St John's College, University of Oxford. Dissertation: "Functional Cryptography". Supervised by Prof Richard Brent.
2001-2004 DPhil in Computer Science at St John's College, University of Oxford. Thesis: "Obfuscation of Abstract Data-Types". Supervised by Dr Jeff Sanders.
2005 Research Assistant in e-learning at the University of Hull. Worked on a European project looking at Intercultural Education in schools.
2006 Moved to the University of Auckland.

A slightly more detailed CV.

Contact Details

E-mail: stephen (at) cs.auckland.ac.nz
Mail:: Stephen Drape
Department of Computer Science
University of Auckland
Private Bag 92019, Auckland
New Zealand
Phone:: +(64 9) 3737 599 x82289 (office)