Illinois Faculty Provide Secure Digital Contract Tracing Option
6/22/2020 5:59:38 PM
A pair of Illinois CS professors and a colleague from the University of Illinois at Chicago (UIC) have developed a novel contact tracing method which they believe has enhanced privacy and security measures that could be deployed to help slow the spread of COVID-19 in the coming months.
Madhusudan Parthasarathy, Ling Ren and UIC and Discovery Partners Institute professor Venkat Venkatakrishnan describe their Contact Tracing Illinois (ConTraIL) method in a white paper. They claim their protocols have two unique features that other apps lack—protection against relay attacks and a way to sunset a user’s data once it goes beyond 14 days, which is the length of time a patient could be infectious.
Contact tracing, along with testing, aims to slow the spread of COVID-19, by identifying, assessing and managing people who may have come in contact with someone who was diagnosed with the disease; it was quite effective in helping slow the spread of COVID-19 in South Korea, after that country drew upon lessons learned during the 2015 outbreak of Middle East Respiratory Syndrome (MERS).
Many health departments nationwide have been manually implementing the practice to prevent a second wave of infection by interviewing recently diagnosed patients and tracking down anyone who had close contact with them during the previous two weeks and encouraging the contacts to self-quarantine.
In general, digital contact tracing uses smart phones to determine who people have been in close proximity to for a specific length of time. If a person tests positive for COVID-19, software on the phone can alert a network of people of the diagnosis and offer information on testing and next steps.
“Digital contact tracing is complementary to manual tracing, and it’s extremely cheap to do, and it’s automatic,” said Parthasarathy. “It also identifies contacts that manual contact tracing may miss such as strangers you are near in an aisle of a grocery store.”
Nationwide, each state will soon endorse a digital platform, providing its residents with an opt-in measure to help control potential disease spread. As of early June, several states have selected Apple and Google’s Exposure Notifications application programming interfaces to help track COVID-19’s contact tracing.
According to Parthasarathy, Apple and Google are in a unique position as platform providers, which can lead to higher adoption rates among countries and health authorities.
“However, public health officials and users want to track locations to help evaluate exposure risks and identify hot spots, which Apple and Google do not allow,” he said.
ConTraIL deploys context signature verification to prevent long-range relay attacks, where a malicious user can relay signals from a person’s smartphone to create a false contact between users who are actually nowhere near each other geographically.
Their protocol is also based on the Reveal X policy, with X being the information that notified users receive to learn about their exposure from those diagnosed with the virus. This policy also ensures that no information about undiagnosed users is revealed to anyone.
“Our approach has a robustness against relay attacks, which would lead to false positives and eventually decrease people’s confidence in the app,” said Ren. “We also implement a way for the system to forget the data once it becomes outdated—past the 14-day window.”
Parthasarathy is confident that the ConTRaIL technology is the best platform in terms of security and privacy. “We recommend that states, including Illinois, adopt it for their contact tracing,” he said. “We also hope universities, including the U of I, will adopt our protocols as campuses welcome students back in the fall.”