I returned to graduate school in fall 2003 after four years helping build a company. My advisor was Ninghui Li. The other members of my thesis committee were Profs. Mike Atallah, Elisa Bertino and Gene Spafford. I graduated with the Ph.D. in December 2005 and accepted a position in the Security and Privacy Technology Lab of Motorola Labs in Schaumburg, IL. My dissertation is titled, "A Theory Based on Security Analysis for Comparing the Expressive Power of Access Control Models."
Research
I work in computer security. My primary interests are in foundational and applied aspects of access control. I have worked also on vulnerability analysis and backward-compatible solutions to security problems in network protocols.
Publications
Journals
Tripunitara, M.V. and Li, N. 2007. A Theory for Comparing the Expressive Power of Access Control Models. Journal of Computer Security (JCS) 15, 2, 231--272. PDF
Li, N. and Tripunitara, M.V. 2006. Security Analysis in Role-Based Access Control. ACM Transactions on Information and Systems Security (TISSEC) 9, 4 (November), 391--420. PDF
Li, N., Tripunitara, M.V. and Bizri, Z. On Mutually-Exclusive Roles and Separation of Duty. Accepted to appear, ACM Transactions on Information and Systems Security (TISSEC). PDF
Under Review:
Tripunitara, M.V. and Li, N. The Foundational Work of Harrison-Ruzzo-Ullman Revisited. Under review, Information Processing Letters. PDF
Jha, S., Li, N., Tripunitara, M.V., Wang, Q. and Winsborough, W. Towards Formal Verification of Role-Based Access Control Policies. Under review, IEEE Transactions on Dependable and Secure Computing (TDSC). PDF
Technical Magazines
Tripunitara, M. V. and Messerges, T. 2007. Resolving the Micropayment Problem. IEEE Computer 40, 2 (February), 104--106. PDF
Tripunitara, M.V. and Spafford, E. 2001. Connectivity Provisioning with Security Attributes. Software Focus 2, 3, 112--116.
Conferences
Li, N., Tripunitara, M.V. and Wang, Q. 2006. Resiliency Policies in Access Control. ACM Conference on Computer and Communications Security (CCS'06), 113--123. PDF
Li, N. and Tripunitara, M.V. 2005. On Safety in Discretionary Access Control. IEEE Symposium on Security and Privacy, 96--109. PDF
Tripunitara, M.V. and Li, N. 2004. Comparing the Expressive Power of Access Control Models. ACM Conference on Computer and Communications Security (CCS'04), 62--71. PDF
Li, N., Bizri, Z. and Tripunitara, M.V. 2004. On Mutually-Exclusive Roles and Separation of Duty. ACM Conference on Computer and Communications Security (CCS'04), 42--51. PDF
Li, N. and Tripunitara, M.V. 2004. Security Analysis in Role-Based Access Control. ACM Symposium on Access Control, Models and Technologies (SACMAT), 126--135. PDF
Tripunitara, M.V. and Dutta, P. 1999. A Middleware Approach to Asynchronous and Backward-Compatible Detection and Prevention of ARP Cache Poisoning. Annual Computer Security Applications Conference (ACSAC'99), 303--309. PDF
Krsul, I., Spafford, E. and Tripunitara, M.V. 1998. An Analysis of Some Software Vulnerabilities. National Information Systems Security Conference (NISSC).
Patents
A Middleware Approach to Asynchronous and Backward-Compatible Detection and Prevention of ARP Cache Poisoning, US Patent Number 6,771,649, Granted August 2004.
Awards
Diamond award for dissertation work, CERIAS, Purdue University, May 2006.
Symantec Fellowship, 2004-2006.
Inducted into the Upsilon Pi Epsilon (UPE) honor society, May 1995.
Service
Program Committee: Semantic Web and Policy Workshop 2005 (SWPW'05), Models of Trust for the Web 2006 (MTW'06).
Publications Chair, Symposium on Network and Distributed Systems Security (NDSS); 2001, 2002, 2003
Scribe, Symposium on Network and Distributed Systems Security (NDSS); 1999, 2000
Reviewer for numerous conferences and journals, including Journal of Computer Security (2004-2006), Computer Networks Journal (2007), ACM SACMAT (2004, 2005), ACM CCS (2004-2006), POLICY Workshop (2005) and NDSS (2004).
Recreation
Here is the page of Spaf's analogies. Last updated November 2003.
A picture of my wife, Pattie, and I. This was taken outside the Snite Museum of Art, University of Notre Dame, in late 2004.
