Interoperable strategies in automated trust negotiation

ABSTRACT

Automated trust negotiation is an approach to establishing trust between strangers through the exchange of digital credentials and the use of access control policies that specify what combinations of credentials a stranger must disclose in order to gain access to each local service or credential. We introduce the concept of a trust negotiation protocol, which defines the ordering of messages and the type of information messages will contain. To carry out trust negotiation, a party pairs its negotiation protocol with a trust negotiation strategy that controls the exact content of the messages, i.e., which credentials to disclose, when to disclose them, and when to terminate a negotiation. There are a huge number of possible strategies for negotiating trust, each with different properties with respect to speed of negotiations and caution in giving out credentials and policies. In the autonomous world of the Internet, entities will want the freedom to choose negotiation strategies that meet their own goals, which means that two strangers who negotiate trust will often not use the same strategy. To date, only a tiny fraction of the space of possible negotiation strategies has been explored, and no two of the strategies proposed so far will interoperate. In this paper, we define a large set of strategies called the disclosure tree strategy (DTS) family. Then we prove that if two parties each choose strategies from the DTS family, then they will be able to negotiate trust as well as if they were both using the same strategy. Further, they can change strategies at any point during negotiation. We also show that the DTS family is closed, i.e., any strategy that can interoperate with every strategy in the DTS family must also be a member of the DTS family. We also give examples of practical strategies that belong to the DTS family and fit within the TrustBuilder architecture and protocol for trust negotiation.

REFERENCES

• 1: Krzysztof R. Apt , David S. Warren , Mirek Truszczynski, The Logic Programming Paradigm: A 25-Year Perspective, Springer-Verlag New York, Inc., Secaucus, NJ, 1999
• 2: M.Blaze,J.Feigenbaum,J.Ioannidis,and A.Keromytis.The KeyNote Trust Management System Version 2.In Internet Draft RFC 2704 , September 1999.
• 3: Matt Blaze , Joan Feigenbaum , Angelos D. Keromytis, KeyNote: Trust Management for Public-Key Infrastructures (Position Paper), Proceedings of the 6th International Workshop on Security Protocols, p.59-63, April 15-17, 1998
• 4: Piero Bonatti , Pierangela Samarati, Regulating service access and information release on the Web, Proceedings of the 7th ACM conference on Computer and communications security, p.134-143, November 01-04, 2000, Athens, Greece [doi>10.1145/352600.352620]
• 5: T.Dierks and C.Allen.The TLS Protocol Version 1.0. In http://www.ietf.org/rfc/rfc2246.txt ,January 1999.
• 6: S.Farrell.TLS Extension for Attribute Certi .cate Based Authorization.In http://www.ietf.org/internetdrafts/draft-ietf-tls-attr-cert-01.txt ,August 1998.
• 7: A.Frier,P.Karlton,and P.Kocher.The SSL 3.0 Protocol .Netscape Communications Corp.,November 1996.
• 8: Amir Herzberg , Yosi Mass , Joris Michaeli , Yiftach Ravid , Dalit Naor, Access Control Meets Public Key Infrastructure, Or: Assigning Roles to Strangers, Proceedings of the 2000 IEEE Symposium on Security and Privacy, p.2, May 14-17, 2000
• 9: http://www.ietf.org/html.charters/spki-charter.html. Simple Public Key Infrastructure (SPKI).
• 10: International Telecommunication Union.Rec.X.509 - Information Technology -Open Systems Interconnection -The Directory:Authentication Framework ,August 1997.
• 11: William Johnston , Srilekha Mudumbai , Mary Thompson, Authorization and Attribute Certificates for Widely Distributed Access Control, Proceedings of the 7th Workshop on Enabling Technologies: Infrastructure for Collaborative Enterprises, p.340-345, June 17-19, 1998
• 12: K.Seamons,M.Winslett,and T.Yu.Limiting the Disclosure of Access Control Policies during Automated Trust Negotiation.In Network and Distributed System Security Symposium ,San Diego, CA,April 2001.
• 13: W3C, http://www.w3.org/TR/WD-P3P/Overview.html. Platform for Privacy Preferences (P3P)Speci .cation .
• 14: W.Winsborough,K.Seamons,and V.Jones. Automated Trust Negotiation.In DARPA Information Survivability Conference and Exposition , Hilton Head,SC,January 2000.
• 15: Ting Yu , Xiaosong Ma , Marianne Winslett, PRUNES: an efficient and complete strategy for automated trust negotiation over the Internet, Proceedings of the 7th ACM conference on Computer and communications security, p.210-219, November 01-04, 2000, Athens, Greece [doi>10.1145/352600.352633]
• 16: T.Yu,M.Winslett,and K.Seamons.Interoperable Strategies in Automated Trust Negotiation.In http://drl.cs.uiuc.edu/pubs/ccs2001-long.ps .
• 17: P.Zimmerman.PGP User 's Guide MIT Press,1994.

INDEX TERMS

Primary Classification:
  K. Computing Milieux
  K.4 COMPUTERS AND SOCIETY
      K.4.4 Electronic Commerce
          Subjects: Electronic data interchange (EDI)

Additional Classification:
  G. Mathematics of Computing
  G.2 DISCRETE MATHEMATICS
      G.2.2 Graph Theory
          Subjects: Graph algorithms

  K. Computing Milieux
  K.6 MANAGEMENT OF COMPUTING AND INFORMATION SYSTEMS
      K.6.5 Security and Protection (D.4.6, K.4.2)
          Subjects: Authentication

General Terms:
Algorithms, Design, Security