Signal uses an OTR variant (I believe OTR masks the identity of the sender/receiver) -- not sure how thorough their implementation and protocol are[1]. Although if authorities already have the IP of one user they might gather a list of contacts.
[1] https://en.wikipedia.org/wiki/Signal_Protocol
Signal uses an OTR variant (I believe OTR masks the identity of the sender/receiver) -- not sure how thorough their implementation and protocol are[1]. Although if authorities already have the IP of one user they might gather a list of contacts.
[1] https://en.wikipedia.org/wiki/Signal_Protocol