On April 17, MediaNama conducted a discussion on Aarogya Setu from a privacy standpoint, and whether the app would even accomplish its stated objectives. On the panel were Professors Subhashis Banerjee (IIT Delhi) and Bhaskaran Raman (IIT Bombay), who were among the co-authors of the paper Apps for COVID: to do or not to do; and security researcher Riddhi Shree, who has studied the studied the technical features of the app. The discussion was moderated by MediaNama's Aditi Agrawal. Edited excerpts from the discussion: Issues with Contact Tracing Bluetooth accuracy issues: "Apps like Aarogya Setu primarily use Bluetooth. When two phones come close to each other, they broadcast and attempt to measure distance using the strength of the signal. To avoid noise you have to set a time-bound limit and say that if you received enough exchange of signals in the space of a few minutes, there was a contact," Prof. Banerjee explained. For proximity to be recorded, typically, devices have to be in range for one to five minutes. At the same time, "if you have a very low Bluetooth interval [that is, Bluetooth signal is sent out too often], it drains the battery. But if you reduce frequency [that is, send out fewer signals in a time period], you get false negatives. What is the right balance is unclear, and the app doesn’t make it clear. This will have a bearing on the reliability of the app", Prof. Banerjee said. Accuracy of GPS and cellular signals: "Apart from this, you can…
