Last day (not time) a client last pinged their servers.
Signal’s access to your contacts lets the client (not them):
determine whether the contacts in their address book are Signal users without revealing the contacts in their address book to the Signal service [0].
They’ve been developing/improving contact discovery since at least 2014 [1], I’d wager they know a thing or two about how to do it in a secure and scalable way. If you disagree or have evidence that proves otherwise, I’d love to be enlightened. The code is open [2], anyone is free to test it and publish their findings.
This is incorrect.
They store:
Signal’s access to your contacts lets the client (not them):
They’ve been developing/improving contact discovery since at least 2014 [1], I’d wager they know a thing or two about how to do it in a secure and scalable way. If you disagree or have evidence that proves otherwise, I’d love to be enlightened. The code is open [2], anyone is free to test it and publish their findings.
[0] https://signal.org/blog/private-contact-discovery/
[1] https://signal.org/blog/contact-discovery/
[2] https://github.com/signalapp/ContactDiscoveryService/
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