Probabilistic Model Checking of an Anonymity System

We use the probabilistic model checker PRISM to analyze the Crowds system for anonymous Web browsing. This case study demonstrates how probabilistic model checking techniques can be used to formally analyze security properties of a peer-to-peer group communication system based on random message routing among members. The behavior of group members and the adversary is modeled as a discrete-time Markov chain, and the desired security properties are expressed as PCTL formulas. The PRISM model checker is used to perform automated analysis of the system and verify anonymity guarantees it provides. Our main result is a demonstration of how certain forms of probabilistic anonymity degrade when group size increases or random routing paths are rebuilt, assuming that the corrupt group members are able to identify and/or correlate multiple routing paths originating from the same sender.

[1]  N. S. Barnett,et al.  Private communication , 1969 .

[2]  David Chaum,et al.  Untraceable electronic mail, return addresses, and digital pseudonyms , 1981, CACM.

[3]  Danny Dolev,et al.  On the security of public key protocols , 1981, 22nd Annual Symposium on Foundations of Computer Science (sfcs 1981).

[4]  Saharon Shelah,et al.  Reasoning with Time and Chance , 1982, Inf. Control..

[5]  Micha Sharir,et al.  Probabilistic temporal logics for finite and bounded models , 1984, STOC '84.

[6]  Moshe Y. Vardi.  Automatic verification of probabilistic concurrent finite state programs , 1985, 26th Annual Symposium on Foundations of Computer Science (sfcs 1985).

[7]  James W. Gray,et al.  Toward a mathematical foundation for information flow security , 1991, Proceedings. 1991 IEEE Computer Society Symposium on Research in Security and Privacy.

[8]  Andrea Bianco,et al.  Model Checking of Probabalistic and Nondeterministic Systems , 1995, FSTTCS.

[9]  Paul F. Syverson,et al.  The epistemic representation of information flow security in probabilistic systems , 1995, Proceedings The Eighth IEEE Computer Security Foundations Workshop.

[10]  Steve A. Schneider,et al.  CSP and Anonymity , 1996, ESORICS.

[11]  Thomas A. Henzinger,et al.  Reactive Modules , 1996, Proceedings 11th Annual IEEE Symposium on Logic in Computer Science.

[12]  Gavin Lowe,et al.  Breaking and Fixing the Needham-Schroeder Public-Key Protocol Using FDR , 1996, Softw. Concepts Tools.

[13]  John Ulrich,et al.  Automated Analysis of Cryptographic Protocols Using Mur ' , 1997 .

[14]  John C. Mitchell,et al.  Automated analysis of cryptographic protocols using Mur/spl phi/ , 1997, Proceedings. 1997 IEEE Symposium on Security and Privacy (Cat. No.97CB36097).

[15]  Michael K. Reiter,et al.  Crowds: anonymity for Web transactions , 1998, TSEC.

[16]  Paul F. Syverson,et al.  Anonymous connections and onion routing , 1998, IEEE J. Sel. Areas Commun..

[17]  Christel Baier,et al.  Model checking for a probabilistic branching time logic with fairness , 1998, Distributed Computing.

[18]  Lawrence C. Paulson,et al.  The Inductive Approach to Verifying Cryptographic Protocols , 2021, J. Comput. Secur..

[19]  Geoffrey Smith,et al.  Probabilistic noninterference in a concurrent language , 1998, Proceedings. 11th IEEE Computer Security Foundations Workshop (Cat. No.98TB100238).

[20]  John C. Mitchell,et al.  Probabilistic Polynomial-Time Equivalence and Security Analysis , 1999, World Congress on Formal Methods.

[21]  Paul F. Syverson,et al.  Group Principals and the Formalization of Anonymity , 1999, World Congress on Formal Methods.

[22]  Somesh Jha,et al.  Verifying security protocols with Brutus , 2000, TSEM.

[23]  Ian Clarke,et al.  Freenet: A Distributed Anonymous Information Storage and Retrieval System , 2000, Workshop on Design Issues in Anonymity and Unobservability.

[24]  Ran Canetti.  A unified framework for analyzing security of protocols , 2001, Electron. Colloquium Comput. Complex..

[25]  Marta Z. Kwiatkowska,et al.  PRISM: Probabilistic Symbolic Model Checker , 2002, Computer Performance Evaluation / TOOLS.

[26]  Micah Adler,et al.  An Analysis of the Degradation of Anonymous Protocols , 2002, NDSS.

[27]  Vitaly Shmatikov,et al.  Probabilistic analysis of anonymity , 2002, Proceedings 15th IEEE Computer Security Foundations Workshop. CSFW-15.