Formal Notions of Anonymity for Peer-to-peer Networks

Providing anonymity support for peer-to-peer (P2P) overlay networks is critical. Otherwise, potential privacy attacks (e.g., network address traceback) may deter a storage source from providing the needed data. In this paper we use this practical application scenario to verify our observation that network-based anonymity can be modeled as a complexity based cryptographic problem. We show that, if the routing process between senders and recipients can be modeled as abstract entities, network-based anonymity becomes an analogy of cryptography. In particular, perfect anonymity facing an unbounded traffic analyst corresponds to Shannon’s perfect secrecy facing an unbounded cryptanalyst. More importantly, in this paper we propose Probabilistic Polynomial Route (PPR) model, which is a new polynomially-bounded anonymity model corresponding to the Probabilistic Polynomial Time (PPT ) model in cryptography. Afterwards, network-based anonymity attacks are with no exception in BPP. This phenomenon has not been discovered in previous anonymity research. Keywords—Formal notion of anonymity; Probabilistic Polynomial Route model; Chosen Recipient Attack; Chosen Sender Attack; Chosen Route Attack; P2P network.

[1]  Claude E. Shannon,et al.  Communication theory of secrecy systems , 1949, Bell Syst. Tech. J..

[2]  George Danezis,et al.  Mixminion: design of a type III anonymous remailer protocol , 2003, 2003 Symposium on Security and Privacy, 2003..

[3]  Andreas Pfitzmann,et al.  Anonymity, Unobservability, and Pseudonymity - A Proposal for Terminology , 2000, Workshop on Design Issues in Anonymity and Unobservability.

[4]  David Chaum,et al.  The dining cryptographers problem: Unconditional sender and recipient untraceability , 1988, Journal of Cryptology.

[5]  Silvio Micali,et al.  Probabilistic Encryption , 1984, J. Comput. Syst. Sci..

[6]  Manuel Blum,et al.  How to generate cryptographically strong sequences of pseudo random bits , 1982, 23rd Annual Symposium on Foundations of Computer Science (sfcs 1982).

[7]  Randy H. Katz,et al.  An algebraic approach to practical and scalable overlay network monitoring , 2004, SIGCOMM '04.

[8]  Ben Y. Zhao,et al.  Tapestry: a resilient global-scale overlay for service deployment , 2004, IEEE Journal on Selected Areas in Communications.

[9]  Daniel R. Simon,et al.  Non-Interactive Zero-Knowledge Proof of Knowledge and Chosen Ciphertext Attack , 1991, CRYPTO.

[10]  Mark Handley,et al.  A scalable content-addressable network , 2001, SIGCOMM '01.

[11]  Matthew K. Franklin,et al.  Identity-Based Encryption from the Weil Pairing , 2001, CRYPTO.

[12]  Amos Fiat,et al.  Provable Unlinkability against Traffic Analysis , 2004, Financial Cryptography.

[13]  A. Shamm.  Identity-based cryptosystems and signature schemes , 1985 .

[14]  G. S. Vernam,et al.  Cipher Printing Telegraph Systems For Secret Wire and Radio Telegraphic Communications , 1926, Transactions of the American Institute of Electrical Engineers.

[15]  Arjen K. Lenstra,et al.  Selecting Cryptographic Key Sizes , 2000, Journal of Cryptology.

[16]  Adi Shamir,et al.  Identity-Based Cryptosystems and Signature Schemes , 1984, CRYPTO.

[17]  Ivan Damgård,et al.  Collision Free Hash Functions and Public Key Signature Schemes , 1987, EUROCRYPT.

[18]  Bart Preneel,et al.  Towards Measuring Anonymity , 2002, Privacy Enhancing Technologies.

[19]  Andrei Serjantov,et al.  On the anonymity of anonymity systems , 2004 .

[20]  Moni Naor,et al.  Universal one-way hash functions and their cryptographic applications , 1989, STOC '89.

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

[22]  Daniel R. Simon,et al.  Cryptographic defense against traffic analysis , 1993, STOC.

[23]  George Danezis,et al.  Towards an Information Theoretic Metric for Anonymity , 2002, Privacy Enhancing Technologies.

[24]  Moni Naor,et al.  Non-malleable cryptography , 1991, STOC '91.

[25]  Latanya Sweeney,et al.  k-Anonymity: A Model for Protecting Privacy , 2002, Int. J. Uncertain. Fuzziness Knowl. Based Syst..

[26]  David R. Karger,et al.  Chord: A scalable peer-to-peer lookup service for internet applications , 2001, SIGCOMM '01.

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

[28]  Paul F. Syverson,et al.  Anonymous connections and onion routing , 1997, Proceedings. 1997 IEEE Symposium on Security and Privacy (Cat. No.97CB36097).

[29]  Rafail Ostrovsky,et al.  Xor-trees for efficient anonymous multicast and reception , 2000, TSEC.

[30]  Moni Naor,et al.  Public-key cryptosystems provably secure against chosen ciphertext attacks , 1990, STOC '90.

[31]  Nicholas Hopper,et al.  k-anonymous message transmission , 2003, CCS '03.