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User:Bravetheif/Digital contact tracing

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Example proposal for a location-based COVID-19 contact tracing app: Contacts of individual A (and all individuals using the app) are traced using GPS co-localisations with other app users, supplemented by scanning QR codes displayed on high-traffic public amenities where GPS is too coarse. Individual A requests a SARS-COV-2 test (using the app) and their positive test result triggers an instant notification to individuals who have been in close contact. The app advises isolation for the case (individual A) and quarantine of their contacts.[1]

Digital contact tracing is a method of contact tracing that takes advantage of mobile devices to determine contact between an infected patient and a user. Although a substantial body of literature on the subject existed as early as 2013,[2][3][4] it came to public prominence during the 2019–20 coronavirus pandemic.[5][6][7] Since the initial outbreak, many groups have developed nonstandard protocols designed to allow for wide scale digital contact tracing, most notably BlueTrace and the Google / Apple contact tracing project.[8][9] When considering the limitations of mobile devices, there are two competing ways to trace contact: GPS and Bluetooth; each with their own drawbacks. Additionally the protocols can either be centralized or decentralized, meaning contact history can either be processed by a central health authority, or by individual clients in the network.

History

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Digital contact tracing has existed as a concept for over a decade,[10][11][12] but was largely held back by the necessity of widespread adoption to be effective.[13] Digital contact tracing was first tested in 2015 during an Ebola outbreak in Guinea, where it found some success in mitigating the severity of the outbreak.[14] The concept truly came to prominence during the 2019–20 coronavirus pandemic,[15][16] where it was deployed on a wide scale for the first time through multiple government and private COVID-19 apps.[17][18] Many countries however saw poor adoption, with Singapore's digital contact tracing app, TraceTogether, seeing an adoption rate of only 10-20%.[19] Apps were often met with overwhelming criticism about concerns with the data health authorities were collecting.[20][21][22] Experts also criticized protocols like the Pan-European Privacy-Preserving Proximity Tracing and BlueTrace for their centralized contact log processing, that meant, unlike with decentralized protocols, the government could determine who you had been in contact with.[23][24][25][26][27]

Methodologies

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Bluetooth contact tracing

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Currently all major digital contact tracing apps use Bluetooth, more specifically Bluetooth Low Energy, to track encounters.[28][29][30] Typically, Bluetooth is used to transmit anonymous, time-shifting identifiers to nearby devices. Receiving devices then commit these identifiers to a locally stored contact history log.

Bluetooth protocols are predominately favored over their location based counterparts because of their much stronger privacy protections and lower battery usage.[8]: table. 1  Because a user's location is not logged as part of the protocols, their location cannot be tracked. The biggest drawback of using a Bluetooth system is the inability to track patients who may have become infected by touching a surface an ill patient has also touched.

Location contact tracing

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No digital contact tracing apps currently make use of GPS, however some implementations do make use of network-based location tracking. This approach has the advantage of eliminating the need to download an app. The first contact tracing protocol of this type was deployed in Israel,[31] however all location based solutions that have access to raw location data have significant privacy problems.[32]

Contact log processing

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Centralized

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When a patient tests positive for infection, a centralized system such as BlueTrace or PEPP-PT requires them to upload their contact history log to a central server, where the health authority would match the identifiers with user records and contact people who came in close contact with the patient.[33]

Decentralized

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Decentralized systems such as the TCN Protocol have the user upload to the central server a token that has no intrinsic information, but can then be used by client devices to derive and match contact history identifiers.[34] Because contact logs are never transmitted to third parties, it has major privacy benefits over approaches like the one used in BlueTrace.[35][36] However this comes at the cost of requiring more computing power on the client side to process infection reports,[37] and does not allow for human-in-the-loop reporting.[38]: p. 6 

Identification

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When two devices meet they need an initially anonymous unique identifier that can later be given meaning if a user tests positive for infection. Additionally, identifiers cannot remain static otherwise malicious third parties can observe identifiers over time across a wide area and identify patterns of movement for individual clients on the network.

Ephemeral ID

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The majority of protocols make use of Ephemeral IDs, which are strings used to identify clients for a short period of time. While not unique for every encounter, ephemeral IDs make it extremely difficult to track individuals over a period of time longer than the lifetime of the ID. When used in a centralized model, such as BlueTrace, Ephemeral IDs are typically the static user identifier and other data encrypted by a key known only to the server. In a decentralized model they are usually pseudo-randomly generated using a seed known only to the client.

Unique ID

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Unique ID protocols generate a new identifier for every encounter. Currently the only protocol using this method is the TCN Protocol. The largest issue with using unique IDs for every encounter is that reports can quickly become extremely large, which, when used in combination with a decentralized model, could lead to extremely large download sizes for clients retrieving reports. TCN overcame this obstacle by instead successively and deterministically generating each new unique ID from the previous. Then, when a report needed to be upload, only the first entry within the report time period was submitted and clients would calculate the rest of the entries locally.

List of protocols

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Name Technology Architecture Author/promoter Licence Homepage Ref
Pan-European Privacy-Preserving Proximity Tracing (PEPP-PT) project Bluetooth LE Central log processing, Ephemeral IDs Fraunhofer Institute for Telecommunications, Robert Koch Institute, Technical University of Berlin, TU Dresden, University of Erfurt, Vodafone Germany multiple protocols, closed source, private specifications https://www.pepp-pt.org/ [39]
Google / Apple privacy-preserving tracing project Bluetooth LE Client log processing, Ephemeral IDs Google, Apple Inc. public specification https://www.apple.com/covid19/contacttracing [40]
Decentralized Privacy-Preserving Proximity Tracing (DP-3T) Bluetooth LE Client log processing,

Ephemeral IDs

EPFL, ETHZ, KU Leuven, TU Delft, University College London, CISPA, University of Oxford, University of Torino / ISI Foundation publicly-developed Apache 2.0 reference implementation, MPL 2.0 iOS/Android code.
 https://github.com/DP-3T [41]
BlueTrace / OpenTrace Bluetooth LE Central log processing,

Ephemeral IDs

Singapore Government Digital Services public specification, GPL 3 code bluetrace.io [42]
TCN Coalition / TCN Protocol Bluetooth LE Client log processing,

Unique IDs

CovidWatch, CoEpi, ITO, Commons Project, Zcash Foundation, Openmined public developed specification, MIT License code tcn-coalition.org https://github.com/TCNCoalition/TCN [40]
Privacy Automated Contact Tracing (East Coast PACT) Bluetooth LE Client log processing,

Ephemeral IDs

Massachusetts Institute of Technology, ACLU, Brown University, Weizmann Institute, Thinking Cybersecurity, Boston University MIT License pact.mit.edu [43]
Privacy-Sensitive Protocols And Mechanisms for Mobile Contact Tracing (West Coast PACT) Bluetooth LE Client log processing, Ephemeral IDs University of Washington, University of Pennsylvania, Microsoft arxiv.org/pdf/2004.03544.pdf [44]

See also

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References

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  1. ^ Ferretti, Luca; Wymant, Chris; Kendall, Michelle; Zhao, Lele; Nurtay, Anel; Abeler-Dörner, Lucie; Parker, Michael; Bonsall, David; Fraser, Christophe (2020-03-31). "Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing". Science. doi:10.1126/science.abb6936. ISSN 0036-8075. PMID 32234805.
  2. ^ Bell, James; Butler, David; Hicks, Chris; Crowcroft, Jon (2020-04-08). "TraceSecure: Towards Privacy Preserving Contact Tracing". arXiv:2004.04059 [cs].
  3. ^ Altuwaiyan, Thamer; Hadian, Mohammad; Liang, Xiaohui (May 2018). "EPIC: Efficient Privacy-Preserving Contact Tracing for Infection Detection". 2018 IEEE International Conference on Communications (ICC). Kansas City, MO: IEEE: 1–6. doi:10.1109/ICC.2018.8422886. ISBN 978-1-5386-3180-5.
  4. ^ Rui Zhang; Jinxue Zhang; Yanchao Zhang; Jinyuan Sun; Guanhua Yan (September 2013). "Privacy-Preserving Profile Matching for Proximity-Based Mobile Social Networking". IEEE Journal on Selected Areas in Communications. 31 (9): 656–668. doi:10.1109/JSAC.2013.SUP.0513057. ISSN 0733-8716.
  5. ^ Bogle, Ariel (2020-04-17). "Five questions we need answered about the government's coronavirus contact tracing app". ABC News. Retrieved 2020-04-18.
  6. ^ Kim, Max S. "Seoul's Radical Experiment in Digital Contact Tracing". The New Yorker. Retrieved 2020-04-18.
  7. ^ Shendruk, Amrita Khalid, Amanda. "How Bluetooth could bring digital contact tracing for Covid-19 to billions". Quartz. Retrieved 2020-04-18.{{cite web}}: CS1 maint: multiple names: authors list (link)
  8. ^ a b Jason Bay, Joel Kek, Alvin Tan, Chai Sheng Hau, Lai Yongquan, Janice Tan, Tang Anh Quy. "BlueTrace: A privacy-preserving protocol for community-driven contact tracing across borders" (PDF). Government Technology Agency. Retrieved 12 April 2020.{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: url-status (link)
  9. ^ "Privacy-Preserving Contact Tracing". Apple. Retrieved 2020-04-19.{{cite web}}: CS1 maint: url-status (link)
  10. ^ Bahri, Shamshul (2007-01-01). "Enhancing quality of data through automated SARS contact tracing method using RFID technology". International Journal of Networking and Virtual Organisations. 4 (2): 145–162. doi:10.1504/IJNVO.2007.013540. ISSN 1470-9503.
  11. ^ Bahri, Shamshul (2007-01-01). "Enhancing quality of data through automated SARS contact tracing method using RFID technology". International Journal of Networking and Virtual Organisations. 4 (2): 145–162. doi:10.1504/IJNVO.2007.013540. ISSN 1470-9503.
  12. ^ Farrahi, Katayoun; Emonet, Rémi; Cebrian, Manuel (2014-05-01). "Epidemic Contact Tracing via Communication Traces". PLoS ONE. 9 (5). doi:10.1371/journal.pone.0095133. ISSN 1932-6203. PMC 4006791. PMID 24787614.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  13. ^ Huang, Yasheng; Sun, Meicen; Sui, Yuze (2020-04-15). "How Digital Contact Tracing Slowed Covid-19 in East Asia". Harvard Business Review. ISSN 0017-8012. Retrieved 2020-04-22.
  14. ^ Sacks, Jilian A.; Zehe, Elizabeth; Redick, Cindil; Bah, Alhoussaine; Cowger, Kai; Camara, Mamady; Diallo, Aboubacar; Gigo, Abdel Nasser Iro; Dhillon, Ranu S.; Liu, Anne (2015-12-01). "Introduction of Mobile Health Tools to Support Ebola Surveillance and Contact Tracing in Guinea". Global Health: Science and Practice. 3 (4): 646–659. doi:10.9745/GHSP-D-15-00207. ISSN 2169-575X. PMID 26681710.
  15. ^ Ferretti, Luca; Wymant, Chris; Kendall, Michelle; Zhao, Lele; Nurtay, Anel; Abeler-Dörner, Lucie; Parker, Michael; Bonsall, David; Fraser, Christophe (2020-03-31). "Quantifying SARS-CoV-2 transmission suggests epidemic control with digital contact tracing". Science. doi:10.1126/science.abb6936. ISSN 0036-8075. PMID 32234805.
  16. ^ Luca Ferretti, Chris Wymant, Michelle Kendall, Lele Zhao, Anel Nurtay, David Bonsall, Christophe Fraser. "Quantifying dynamics of SARS-CoV-2 transmission suggests that epidemic control and avoidance is feasible through instantaneous digital contact tracing" (PDF). medRxiv.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  17. ^ Choudhury, Saheli Roy (2020-03-25). "Singapore says it will make its contact tracing tech freely available to developers". CNBC. Retrieved 2020-04-22.
  18. ^ Barbaschow, Asha. "Australia looks to 'go harder' with use of COVID-19 contact tracing app". ZDNet. Retrieved 2020-04-22.
  19. ^ "Virus tracing apps 'ready in weeks' in EU and Australia". BBC News. 2020-04-17. Retrieved 2020-04-22.
  20. ^ Taylor, Josh (2020-04-21). "Australia's coronavirus contact tracing app: what we know so far". The Guardian. ISSN 0261-3077. Retrieved 2020-04-22.
  21. ^ "The GPS tracking app the government wants YOU to download so COVID lockdown can be lifted". 7NEWS.com.au. 2020-04-15. Retrieved 2020-04-22.
  22. ^ "Privacy recommendations for Australia's use of contact tracing mobile apps like TraceTogether". australiancybersecuritymagazine.com.au. Retrieved 2020-04-22.{{cite web}}: CS1 maint: url-status (link)
  23. ^ "Das gefährliche Chaos um die Corona-App". www.tagesspiegel.de (in German). Retrieved 2020-04-20.
  24. ^ "ZEIT ONLINE | Lesen Sie zeit.de mit Werbung oder imPUR-Abo. Sie haben die Wahl". www.zeit.de. Retrieved 2020-04-20.
  25. ^ SPIEGEL, DER. "Projekt Pepp-PT: Den Tracing-App-Entwicklern laufen die Partner weg - DER SPIEGEL - Netzwelt". www.spiegel.de (in German). Retrieved 2020-04-20.
  26. ^ Zeitung, Süddeutsche. "Corona-App: Streit um Pepp-PT entbrannt". Süddeutsche.de (in German). Retrieved 2020-04-20.
  27. ^ editor, Alex Hern Technology (2020-04-20). "Digital contact tracing will fail unless privacy is respected, experts warn". The Guardian. ISSN 0261-3077. Retrieved 2020-04-20. {{cite news}}: |last= has generic name (help)
  28. ^ "Is Apple and Google's Covid-19 Contact Tracing a Privacy Risk?". Wired. ISSN 1059-1028. Retrieved 2020-04-18.
  29. ^ Wetsman, Nicole (2020-04-15). "Google and Apple's COVID-19 tracking system can't save lives all on its own". The Verge. Retrieved 2020-04-18.
  30. ^ "Explainer: How smartphone apps can help 'contact trace' the new coronavirus". Reuters. 2020-04-14. Retrieved 2020-04-18.
  31. ^ Holmes, Oliver (2020-03-17). "Israel to track mobile phones of suspected coronavirus cases". The Guardian. ISSN 0261-3077. Retrieved 2020-04-01.
  32. ^ "ACLU White Paper: The Limits of Location Tracking in an Epidemic". American Civil Liberties Union. Retrieved 2020-04-10.
  33. ^ Jackson, Carl (2020-04-06). "TraceTogether, Singaporean COVID-19 contact tracing and Australian recommendations". Melbourne School of Engineering. Retrieved 2020-04-18.
  34. ^ TCNCoalition/TCN, TCN Coalition, 2020-04-18, retrieved 2020-04-18
  35. ^ "Aisshwarya Tiwar: COVID-19: Zcash (ZEC) and TCN Developing Privacy-Preserving Contact Tracing App | IoT Council". www.theinternetofthings.eu. Retrieved 2020-04-19. {{cite web}}: no-break space character in |title= at position 98 (help)CS1 maint: url-status (link)
  36. ^ "COVID-19: Zcash (ZEC) and TCN Developing Privacy-Preserving Contact Tracing App | BTCMANAGER". btcmanager. 2020-04-12. Retrieved 2020-04-19.{{cite web}}: CS1 maint: url-status (link)
  37. ^ "DP-3T 3 page brief" (PDF). GitHub. Retrieved 2020-04-22.{{cite web}}: CS1 maint: url-status (link)
  38. ^ Jason Bay, Joel Kek, Alvin Tan, Chai Sheng Hau, Lai Yongquan, Janice Tan, Tang Anh Quy. "BlueTrace: A privacy-preserving protocol for community-driven contact tracing across borders" (PDF). Government Technology Agency. Retrieved 2020-04-12.{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: url-status (link)
  39. ^ "An EU coalition of techies is backing a 'privacy-preserving' standard for COVID-19 contacts tracing". TechCrunch. Retrieved 2020-04-02.
  40. ^ a b Sam Schechner and Rolfe Winkler (2020-04-11). "Here's How Apple and Google Plan to Track the Coronavirus Through Your Phone". The Wall Street Journal. Retrieved 2020-04-11.{{cite news}}: CS1 maint: url-status (link)
  41. ^ "Call for common EU approach to apps and data to fight COVID-19 and protect citizens' rights". TechCrunch. 2020-04-08. Retrieved 2020-04-13.
  42. ^ Jason Bay, Joel Kek, Alvin Tan, Chai Sheng Hau, Lai Yongquan, Janice Tan, Tang Anh Quy. "BlueTrace: A privacy-preserving protocol for community-driven contact tracing across borders" (PDF). Government Technology Agency. Retrieved 2020-04-12.{{cite web}}: CS1 maint: multiple names: authors list (link) CS1 maint: url-status (link)
  43. ^ The PACT protocol specification (PDF). MIT. 2020.
  44. ^ Justin Chan, Dean Foster, Shyam Gollakota, Eric Horvitz, Joseph Jaeger, Sham Kakade, Tadayoshi Kohno, John Langford, Jonathan Larson, Sudheesh Singanamalla, Jacob Sunshine, Stefano Tessaro (2020). PACT: Privacy-Sensitive Protocols And Mechanisms for Mobile Contact Tracing (PDF).{{cite book}}: CS1 maint: multiple names: authors list (link)
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