Papers
Topics
Authors
Recent
Gemini 2.5 Flash
Gemini 2.5 Flash 96 tok/s
Gemini 2.5 Pro 51 tok/s Pro
GPT-5 Medium 35 tok/s
GPT-5 High 43 tok/s Pro
GPT-4o 106 tok/s
GPT OSS 120B 460 tok/s Pro
Kimi K2 228 tok/s Pro
2000 character limit reached

Mutual Contact Discovery (2209.12003v4)

Published 24 Sep 2022 in cs.CY

Abstract: Contact discovery allows new users of a messaging service to find existing contacts that already use that service. Existing users are similarly informed of new users that join. This creates a privacy issue: anyone already on the service that has your number on their contact list gets notified that you joined. Even if you don't know that person, or if it is an ex or former colleague that you long parted with and whose contact details you deleted long ago. To solve this, we propose a mutual contact discovery protocol, that only allow users to discover each other when both are (still) in each other's contact list. Mutual contact discovery has the additional advantage that it can be implemented in a more privacy friendly fashion (e.g. protecting the social graph from the server) than traditional, one-sided contact discovery, without necessarily relying on trusted hardware.

Definition Search Book Streamline Icon: https://streamlinehq.com
References (40)
  1. Adam Back “Hashcash - A Denial of Service Counter-Measure”, http://www.cypherspace.org/hashcash, 1997
  2. Robert W. Baldwin and Wayne C. Gramlich “Cryptographic Protocol for Trustable Match Making” In 1985 IEEE S&P IEEE Comp. Soc., 1985, pp. 92–100
  3. “Secret Handshakes from Pairing-Based Key Agreements” In 2003 IEEE S&P IEEE Comp. Soc., 2003, pp. 180–196
  4. “Random oracles are practical: A paradigm for designing efficient protocols” In CCS 1993 ACM, 1993, pp. 62–73
  5. “Argon2 Memory-Hard Function for Password Hashing and Proof-of-Work Applications” RFC Editor, Internet Requests for Comments, 2016, pp. 1–21 URL: http://www.rfc-editor.org/rfc/rfc9106.txt
  6. “Identity-based encryption from the Weil pairing” In SIAM J. Comput. 32.3, 2003, pp. 586–615
  7. “How to win the clonewars: efficient periodic n-times anonymous authentication” In CCS 2006 ACM, 2006, pp. 201–210
  8. “A Formal Treatment of Onion Routing” In CRYPTO 2005, LNCS 3612 Springer, 2005, pp. 169–187
  9. “An Efficient System for Non-transferable Anonymous Credentials with Optional Anonymity Revocation” In EUROCRYPT 2001, LNCS 2045 Springer, 2001, pp. 93–118 DOI: 10.1007/3-540-44987-6
  10. Ran Canetti “Universally Composable Security: A New Paradigm for Cryptographic Protocols” In 42nd FOCS IEEE Comp. Soc., 2001, pp. 136–145
  11. “UDM: Private user discovery with minimal information disclosure” In Cryptologia 46.4, 2022, pp. 347–379 DOI: 10.1080/01611194.2021.1911876
  12. “Labeled PSI from Fully Homomorphic Encryption with Malicious Security” In CCS 2018 ACM, 2018, pp. 1223–1237 URL: https://doi.org/10.1145/3243734.3243836
  13. Hao Chen, Kim Laine and Peter Rindal “Fast Private Set Intersection from Homomorphic Encryption” In CCS 2017 ACM, 2017, pp. 1243–1255 URL: https://doi.org/10.1145/3133956.3134061
  14. “Private information retrieval” In JACM 45.6, 1998, pp. 965–981
  15. Henry Corrigan-Gibbs, Dan Boneh and David Mazières “Riposte: An Anonymous Messaging System Handling Millions of Users” In 2015 IEEE S&P IEEE Comp. Soc., 2015, pp. 321–338 DOI: 10.1109/SP.2015.27
  16. “New directions in cryptography” In IEEE Trans. Inf. Theory IT-11, 1976, pp. 644–654
  17. Roger Dingledine, Nick Mathewson and Paul F. Syverson “Tor: The Second-Generation Onion Router” In 13th USENIX Sec. Symp. USENIX Association, 2004, pp. 303–320
  18. “Pricing via Processing or Combatting Junk Mail” In CRYPTO ’92, LNCS 740 Springer, 1992, pp. 139–147
  19. Michael Freedman, Kobbi Nissim and Benny Pinkas “Efficient private matching and set intersection” In EUROCRYPT 2004, LNCS 3027 Springer, 2004, pp. 1–19
  20. O. Goldreich, S. Micali and A. Wigderson “How to Play ANY Mental Game” In 19th STOC ACM, 1987, pp. 218–229
  21. Oded Goldreich “The Foundations of Cryptography - Volume 2: Basic Applications” Cambridge, UK: Cambridge University Press, 2001
  22. “All the Numbers are US: Large-scale Abuse of Contact Discovery in Mobile Messengers” In NDSS 2021, 2021
  23. “PrivateDrop: Practical Privacy-Preserving Authentication for Apple AirDrop” In 30th USENIX Sec. Symp. USENIX Association, 2021, pp. 3577–3594 URL: https://www.usenix.org/system/files/sec21fall-heinrich.pdf
  24. Jaap-Henk Hoepman “Private Handshakes” In 4th ESAS, LNCS 4572, 2007, pp. 31–42
  25. Jaap-Henk Hoepman “Privately (and Unlinkably) Exchanging Messages Using a Public Bulletin Board” In WPES 2015 ACM, 2016, pp. 85–94 URL: https://dl.acm.org/citation.cfm?doid=2808138.2808142
  26. “Vuvuzela: scalable private messaging resistant to traffic analysis” In Proc. of the 25th Symp. on Operating Systems Principles, SOSP 2015 ACM, 2015, pp. 137–152 DOI: 10.1145/2815400.2815417
  27. IBM Research Zürich Team “Specification of the Identity Mixer Cryptographic Library”, 2012
  28. “Mobile Private Contact Discovery at Scale” In 28th USENIX Sec. Symp. USENIX Association, 2019, pp. 1447–1464 URL: https://www.usenix.org/conference/usenixsecurity19/presentation/kales
  29. B. Kaliski “PKCS #5: Password-Based Cryptography Specification. Version 2.0” RFC Editor, Internet Requests for Comments, 2000 URL: http://www.rfc-editor.org/rfc/rfc2898.txt
  30. “Introduction to Modern Cryptography, Second Edition” Boca Raton: CRC Press, 2014 URL: https://www.crcpress.com/Introduction-to-Modern-Cryptography-Second-Edition/Katz-Lindell/p/book/9781466570269
  31. “Private Set Intersection for Unequal Set Sizes with Mobile Applications” In PoPETs 2017.4, 2017, pp. 177–197 DOI: 10.1515/popets-2017-0044
  32. Yehuda Lindell “How to Simulate It - A Tutorial on the Simulation Proof Technique” In Tutorials on the Foundations of Cryptography Springer International Publishing, 2017, pp. 277–346 DOI: 10.1007/978-3-319-57048-8_6
  33. Moxie Marlinspike “Technology Preview: Private Contact Discovery for Signal”, 2017 URL: https://signal.org/blog/private-contact-discovery/
  34. Moxie Marlinspike “The Difficulty Of Private Contact Discovery”, 2014 URL: https://signal.org/blog/contact-discovery
  35. “Demystifying COVID-19 digital contact tracing: A survey on frameworks and mobile apps” In Wireless Communications and Mobile Computing, 2020, pp. 8851429 DOI: https://doi.org/10.1155/2020/8851429
  36. C. Meadows “A more efficient cryptographic matchmaking protocol for use in the absence of a continuously available third party” In 1986 IEEE S&P IEEE Comp. Soc., 1986, pp. 134–137
  37. “Arke: Scalable and Byzantine Fault Tolerant Privacy-Preserving Contact Discovery” https://eprint.iacr.org/2023/1218, Cryptology ePrint Archive, Paper 2023/1218, 2023 URL: https://eprint.iacr.org/2023/1218
  38. “The scrypt Password-Based Key Derivation Function” RFC Editor, Internet Requests for Comments, 2016, pp. 1–26 URL: http://www.rfc-editor.org/rfc/rfc7914.txt
  39. Douglas Wikström “A Universally Composable Mix-Net” In TCC 2004, LNCS 2951 Springer, 2004, pp. 317–335 DOI: 10.1007/B95566
  40. World Health Organization “Contact tracing in the context of COVID-19, Interim guidance”, 2020 URL: www.who.int/publications/i/item/contact-tracing-in-the-context-of-covid-19
List To Do Tasks Checklist Streamline Icon: https://streamlinehq.com

Collections

Sign up for free to add this paper to one or more collections.

User Circle Single Streamline Icon: https://streamlinehq.com Sign Up

Summary

We haven't generated a summary for this paper yet.

Ai Sparkles Streamline Icon: https://streamlinehq.com Summarize Now
Dice Question Streamline Icon: https://streamlinehq.com

Follow-up Questions

We haven't generated follow-up questions for this paper yet.

Ai Sparkles Streamline Icon: https://streamlinehq.com Generate Now

Authors (1)

  1. Jaap-Henk Hoepman