eprintid: 263247 rev_number: 201 eprint_status: archive userid: 893 source: http://eprints.ecs.soton.ac.uk/id/eprint/13247 dir: disk0/00/26/32/47 datestamp: 2006-12-13 lastmod: 2024-03-14 07:27:53 status_changed: 2011-03-01 11:21:46 type: conference_item metadata_visibility: show item_issues_count: 0 ispublished: pub full_text_status: public keywords: retrenchment, refinement, mondex, electronic purse note: Event Dates: November 19, 2006 date: 2006 event_title: IEEE ISOLA 2006: 2nd Int. Symp. on Leveraging Applications of Formal Methods, Verification and Validation (19/11/06) event_type: conference refereed: TRUE divisions: 03ec46aa-1e95-45b1-ae8b-34b17f3ac30f locs_drange_place: Paphos locs_drange_country: Cyprus locs_drange_venue: IEEE ISOLA 2006: 2nd Int. Symp. on Leveraging Applications of Formal Methods, Verification and Validation locs_drange_start: 2006-11-19 locs_drange_type: event creators_name: Banach, Richard creators_name: Jeske, Czeslaw creators_name: Poppleton, Michael creators_name: Stepney, Susan creators_id: 3c9a2946-4d86-428e-bce2-6dfdde219ff3 creators_id: fbe74737-872a-44ad-9592-d2036aeb95a1 creators_id: 00f3ffec-b4ff-4dd3-89a4-7a9aaff1c9f1 creators_id: 7a80b0af-85d5-4686-87fe-62d782c72156 creators_hidden: FALSE creators_hidden: FALSE creators_hidden: FALSE creators_hidden: FALSE contributors_type: http://www.loc.gov/loc.terms/relators/AUT contributors_type: http://www.loc.gov/loc.terms/relators/AUT contributors_type: http://www.loc.gov/loc.terms/relators/AUT contributors_type: http://www.loc.gov/loc.terms/relators/AUT contributors_type: http://www.loc.gov/loc.terms/relators/EDT contributors_type: http://www.loc.gov/loc.terms/relators/EDT contributors_type: http://www.loc.gov/loc.terms/relators/EDT contributors_name: Banach, Richard contributors_name: Jeske, Czeslaw contributors_name: Poppleton, Michael contributors_name: Stepney, Susan contributors_name: Margaria, Tiziana contributors_name: Philippou, Anna contributors_name: Steffen, Bernhard contributors_id: 3c9a2946-4d86-428e-bce2-6dfdde219ff3 contributors_id: fbe74737-872a-44ad-9592-d2036aeb95a1 contributors_id: 00f3ffec-b4ff-4dd3-89a4-7a9aaff1c9f1 contributors_id: 7a80b0af-85d5-4686-87fe-62d782c72156 contributors_id: 77631364-2e50-4626-8f14-5dd63669c470 contributors_id: 140c2451-d79a-4c10-83b7-e84b547ba8e2 contributors_id: 14184ff8-14ec-4cb3-a58f-73bead1bb1fc contributors_hidden: FALSE contributors_hidden: FALSE contributors_hidden: FALSE contributors_hidden: FALSE contributors_hidden: FALSE contributors_hidden: FALSE contributors_hidden: FALSE title: Retrenching the Purse: Hashing Injective CLEAR Codes, and Security Properties pres_type: paper abstract: The Mondex Electronic Purse is an outstanding example of industrial scale formal refinement, and was the first verification to achieve ITSEC level E6 certification. A formal abstract model and a formal concrete model were developed, and a formal refinement was hand-proved between them. Nevertheless, certain requirements issues were set beyond the scope of the formal development, or handled in an unnatural manner. The retrenchment Tower Pattern is used to address one such issue in detail: the use of a hash function rather than a total injective function when clearing the highly constrained purse logs. A retrenchment is constructed from the lowest level model to a model using a hash, and is then lifted to create two refinement developments, working at different levels of detail, and connected via retrenchments. The tower development is appropriately validated, vindicating the design used. date_type: published pagerange: 76-89 editors_name: Margaria, Tiziana editors_name: Philippou, Anna editors_name: Steffen, Bernhard editors_id: 77631364-2e50-4626-8f14-5dd63669c470 editors_id: 140c2451-d79a-4c10-83b7-e84b547ba8e2 editors_id: 14184ff8-14ec-4cb3-a58f-73bead1bb1fc referencetext: [1] S. Stepney, D. Cooper, and J. Woodcock, “An electronic purse: Specification, refinement and proof,” Oxford University Computing Laboratory, Tech. Rep. PRG-126, 2000. [2] D. of Trade and Industry, “Information Technology Security Evaluation Criteria,” 1991, http://www.cesg.gov.uk/site/iacs/itsec/media/formaldocs/ Itsec.pdf. [3] Common Criteria for Information Security Evaluation, ISO 15408, v. 3.0 rev. 2, 2005. [4] R. Banach and M. Poppleton, “Retrenchment: An engineering variation on refinement,” in 2nd International B Conference, ser. LNCS, D. Bert, Ed., vol. 1393. Montpellier, France: Springer, April 1998, pp. 129–147. [5] ——, “Sharp retrenchment, modulated refinement and simulation,” Formal Aspects of Computing, vol. 11, pp. 498–540, 1999. [6] M. Poppleton and R. Banach, “Controlling control systems: An application of evolving retrenchment,” in Second International Conference of B and Z Users, ser. LNCS, D. Bert, J. Bowen, M. Henson, and K. Robinson, Eds., vol. 2272. Grenoble, France: Springer, January 2002, pp. 42–61. [7] R. Banach and M. Poppleton, “Retrenching partial requirements into system definitions: A simple feature interaction case study,” Requirements Engineering Journal, vol. 8, no. 2, 2003, 22pp. [8] R. Banach, M. Poppleton, C. Jeske, and S. Stepney, “Retrenching the purse: Finite sequence numbers and the tower pattern,” in Formal Methods 2005, ser. LNCS, J. Fitzgerald, I. Hayes, and T. A., Eds., vol. 3582. Newcastle, UK: Springer, 2005, pp. 382–398. [9] R. Banach, C. Jeske, M. Poppleton, and S. Stepney, “Retrenching the purse: Finite exception logs, and validating the small,” in Workshop on Software Engineering 2006, M. Hinchey, Ed. Loyola College, MD: IEEE Computer Society Press, 2006. [10] R. Banach, M. Poppleton, C. Jeske, and S. Stepney, “Retrenching the purse: The balance enquiry quandary, and generalised and (1,1) forward refinements,” Fundamenta Informaticae, 2006, (to appear). [11] C. Jeske, “Algebraic integration of retrenchment and refinement,” Ph.D. dissertation, University of Manchester, 2005. [12] J. Woodcock and J. Davies, Using Z: Specification, Refinement and Proof. Prentice-Hall, 1996. [13] J. Derrick and E. Boiten, Refinement in Z and Object-Z, ser. FACIT. Springer, 2001. [14] S. Stepney, F. Polack, and I. Toyn, “An outline pattern language for Z,” in Third International Conference of B and Z Users, ser. LNCS, D. Bert, J. Bowen, S. King, and M. Wald´en, Eds., vol. 2651. Turku, Finland: Springer, June 2000, pp. 2–19. [15] ——, “Patterns to guide practical refactoring,” in Third International Conference of B and Z Users, ser. LNCS, D. Bert, J. Bowen, S. King, and M. Wald´en, Eds., vol. 2651. Turku, Finland: Springer, June 2000, pp. 20–39. [16] R. Banach, “Maximally abstract retrenchments,” in Proc. IEEE ICFEM2000. York: IEEE Computer Society Press, August 2000, pp. 133–142. [17] D. Bert, J. Bowen, S. King, and M. Wald´en, Eds., Proc. ZB2003: Formal Specification and Development in Z and B, ser. LNCS, vol. 2651. Turku, Finland: Springer, June 2000. languages_3char: eng organisations: Electronics & Computer Science pure_uuid: d2687fd0-dd1e-4f97-aa03-5854038679ed fp7_type: info:eu-repo/semantics/conferenceObject dates_date: 2006 dates_date_type: published hoa_compliant: 304 hoa_date_pub: 2006-12-13 citation: Banach, Richard, Jeske, Czeslaw, Poppleton, Michael and Stepney, Susan (2006) Retrenching the Purse: Hashing Injective CLEAR Codes, and Security Properties. Margaria, Tiziana, Philippou, Anna and Steffen, Bernhard (eds.) IEEE ISOLA 2006: 2nd Int. Symp. on Leveraging Applications of Formal Methods, Verification and Validation, Paphos, Cyprus. pp. 76-89 . document_url: https://eprints.soton.ac.uk/263247/1/Retrench.Mondex.Hash.ISOLA06.pdf