[teo_zero]

How can one be sure that the relay does not record all the data flowing through it? There's not a second independent channel where the key is exchanged between sender and receiver.

[shim__]

The transfer is end2end encrypted using a PAKE key change which is aithenticated using the 3 words you enter in the reveiving end

[teo_zero]

Thank you. I imagined that the 3 words were just a rendez-vous token that the receiving end must hand to the relay to retrieve the right data. I understand that it also includes a password to validate the key.

Are 32 bits enough to serve both functions?

[shim__]

Yes 32 bit is enough because in PAKE its used for authenticstion not encryption. Which means you get exactly one attempt to brute force after which the procedere will fail