DP5: A Private Presence Service

Open access


Users of social applications like to be notified when their friends are online. Typically, this is done by a central server keeping track of who is online and offline, as well as of all of the users’ “buddy lists”, which contain sensitive information. We present DP5, a cryptographic service that implements online presence indication in a privacy-friendly way. DP5 allows clients to register their online presence and query the presence of their list of friends while keeping this list secret. Besides presence, high-integrity status updates are supported, to facilitate key update and rendezvous protocols. While infrastructure services are required for DP5 to operate, they are designed to not require any long-term secrets and provide perfect forward secrecy in case of compromise. We provide security arguments for the indistinguishability properties of the protocol, as well as an evaluation of its scalability and performance.

[1] Diego F. Aranha and Conrado Porto Lopes Gouvêa. RELIC is an Efficient LIbrary for Cryptography. https://github.com/relic-toolkit/relic, 2015.

[2] Roy Arends, Rob Austein, Matt Larson, Dan Massey, and Scott Rose. DNS security introduction and requirements. RFC 4033, http://www.ietf.org/rfc/rfc4033.txt, 2005.

[3] Michael Backes, Ian Goldberg, Aniket Kate, and Tomas Toft. Adding query privacy to robust DHTs. In Heung Youl Youm and Yoojae Won, editors, 7th ACM Symposium on Information, Computer and Communications Security (ASIACCS), pages 30–31. ACM, 2012.

[4] Randolph Baden, Adam Bender, Neil Spring, Bobby Bhattacharjee, and Daniel Starin. Persona: an online social network with user-defined privacy. In Pablo Rodriguez, Ernst W. Biersack, Konstantina Papagiannaki, and Luigi Rizzo, editors, ACM SIGCOMM Conference on Data Communication, pages 135–146. ACM, 2009.

[5] Daniel J. Bernstein. Curve25519: New Diffie-Hellman speed records. In Moti Yung, Yevgeniy Dodis, Aggelos Kiayias, and Tal Malkin, editors, Public Key Cryptography, volume 3958 of Lecture Notes in Computer Science, pages 207–228. Springer, 2006.

[6] Daniel J. Bernstein. DNSCurve: Usable security for DNS. http://dnscurve.org/, 2009.

[7] Daniel J. Bernstein, Niels Duif, Tanja Lange, Peter Schwabe, and Bo-Yin Yang. High-speed high-security signatures. Journal of Cryptographic Engineering, 2(2):77–89, 2012.

[8] Dan Boneh, Craig Gentry, Ben Lynn, and Hovav Shacham. Aggregate and verifiably encrypted signatures from bilinear maps. In Eli Biham, editor, Advances in Cryptology — EUROCRYPT, number 2656 in Lecture Notes in Computer Science, pages 416–432. Springer, January 2003.

[9] Dan Boneh, Ben Lynn, and Hovav Shacham. Short signatures from the Weil pairing. In Colin Boyd, editor, Advances in Cryptology—ASIACRYPT, number 2248 in Lecture Notes in Computer Science, pages 514–532. Springer, January 2001.

[10] Philippe Boucher, Adam Shostack, and Ian Goldberg. Freedom systems 2.0 architecture. White paper, Zero Knowledge Systems, Inc., December 2000.

[11] Jan Camenisch, Susan Hohenberger, Markulf Kohlweiss, Anna Lysyanskaya, and Mira Meyerovich. How to win the clonewars: efficient periodic n-times anonymous authentication. In Ari Juels, Rebecca N. Wright, and Sabrina De Capitani di Vimercati, editors, ACM Conference on Computer and Communications Security, pages 201–210. ACM, 2006.

[12] Sanjit Chatterjee, Darrel Hankerson, Edward Knapp, and Alfred Menezes. Comparing two pairing-based aggregate signature schemes. Designs, Codes and Cryptography, 55(2-3):141–167, May 2010.

[13] David Chaum. The dining cryptographers problem: Unconditional sender and recipient untraceability. Journal of Cryptology, 1(1):65–75, 1988.

[14] Benny Chor, Niv Gilboa, and Moni Naor. Private information retrieval by keywords. Technical Report 1998/003, IACR, 1998. http://eprint.iacr.org/1998/003.ps.

[15] Benny Chor, Oded Goldreich, Eyal Kushilevitz, and Madhu Sudan. Private information retrieval. In 36th Annual Symposium on the Foundations of Computer Science (FOCS), pages 41–50, Oct 1995.

[16] David Cole. We kill people based on metadata. New York Review of Books, May 10 2014.

[17] Henry Corrigan-Gibbs, Dan Boneh, and David Mazieres. Riposte: An anonymous messaging system handling millions of users. In 36th IEEE Symposium on Security and Privacy, May 2015.

[18] Joan Daemen and Vincent Rijmen. The Design of Rijndael: AES—The Advanced Encryption Standard. Springer, 2002.

[19] George Danezis, Claudia Diaz, Carmela Troncoso, and Ben Laurie. Drac: An architecture for anonymous low-volume communications. In Privacy Enhancing Technologies, pages 202–219. Springer, 2010.

[20] Caset Devet, Nadia Heninger, and Ian Goldberg. Optimally robust private information retrieval. In 21st USENIX Security Symposium, Aug 2012.

[21] Casey Devet and Ian Goldberg. The best of both worlds: Combining information-theoretic and computational pir for communication efficiency. In 14th Privacy Enhancing Technologies Symposium, pages 63–82, July 2014.

[22] T. Dierks and E. Rescorla. The transport layer security (TLS) protocol version 1.2. RFC 5246 (Proposed Standard), August 2008.

[23] Whitfield Diffie and Martin E. Hellman. New directions in cryptography. IEEE Transactions on Information Theory, 22(6):644–654, 1976.

[24] Roger Dingledine. Tor security advisory: “relay early” traffic confirmation attack. https://blog.torproject.org/blog/torsecurity-advisory-relay-early-traffic-confirmation-attack, July 2014.

[25] Roger Dingledine, Nick Mathewson, and Paul F. Syverson. Tor: The second-generation onion router. In USENIX Security Symposium, pages 303–320. USENIX, 2004.

[26] John R. Douceur. The Sybil attack. In Peter Druschel, Frans Kaashoek, and Antony Rowstron, editors, Peer-to-Peer Systems, volume 2429 of Lecture Notes in Computer Science, pages 251–260. Springer, 2002.

[27] Donald Eastlake and Paul Jones. US Secure Hash Algorithm 1 (SHA1). RFC 3174, September 2001.

[28] Steven D. Galbraith, Kenneth G. Paterson, and Nigel P. Smart. Pairings for cryptographers. Discrete Applied Mathematics, 156(16):3113–3121, September 2008.

[29] James Glanz, Jeff Larson, and Andrew W. Lehren. Spy agencies tap data streaming from phone apps, January 27 2014.

[30] Ian Goldberg. Improving the robustness of private information retrieval. In IEEE Symposium on Security and Privacy, pages 131–148. IEEE Computer Society, 2007.

[31] Ian Goldberg, Casey Devet, Wouter Lueks, Ann Yang, Paul Hendry, and Ryan Henry. Percy+ + project on SourceForge, October 2014. http://percy.sourceforge.net/.

[32] Aaron Johnson, Chris Wacek, Rob Jansen, Micah Sherr, and Paul Syverson. Users get routed: Traffic correlation on Tor by realistic adversaries. In 20th ACM Conference on Computer and Communications Security (CCS), November 2013.

[33] Ben Laurie. Apres—a system for anonymous presence. http://www.apache-ssl.org/apres.pdf, 2004. Technical report.

[34] Wouter Lueks and Ian Goldberg. Sublinear scaling for multiclient private information retrieval. In 19th International Conference on Financial Cryptography and Data Security, January 2015.

[35] David A McGrew and John Viega. The security and performance of the Galois/Counter Mode (GCM) of operation. In Progress in Cryptology-INDOCRYPT, pages 343–355. Springer, 2005.

[36] Arvind Narayanan and Vitaly Shmatikov. De-anonymizing social networks. In IEEE Symposium on Security and Privacy, pages 173–187. IEEE Computer Society, 2009.

[37] Dominic Rushe. Lavabit founder refused FBI order to hand over email encryption keys. The Guardian, October 3 2013.

[38] Peter Saint-Andre, Kevin Smith, and Remko TronCon. XMPP: The Definitive Guide: Building Real-Time Applications with Jabber Technologies. O’Reilly Media, 1st edition, 2009.

[39] Paul F. Syverson, Gene Tsudik, Michael G. Reed, and Carl E. Landwehr. Towards an analysis of onion routing security. In Hannes Federrath, editor, Workshop on Design Issues in Anonymity and Unobservability, volume 2009 of Lecture Notes in Computer Science, pages 96–114. Springer, 2000.

[40] Henry Tan and Micah Sherr. Censorship resistance as a side-effect. In Security Protocols Workshop, 2014.

[41] Matthias Wachs, Martin Schanzenbach, and Christian Grothoff. On the feasibility of a censorship resistant decentralized name system. In 6th International Symposium on Foundations & Practice of Security (FPS), 2013.

[42] Qiyan Wang and Nikita Borisov. Octopus: A secure and anonymous DHT lookup. In Xavier Defago and Wang-Chien Lee, editors, 32nd IEEE International Conference on Distributed Computing Systems (ICDCS), pages 325–334, June 2012.

[43] David Isaac Wolinsky, Henry Corrigan-Gibbs, Bryan Ford, and Aaron Johnson. Dissent in numbers: Making strong anonymity scale. In 10th USENIX Symposium on Operating Systems Design and Implementation, pages 179–182. USENIX, 2012.

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