News for hackers. Stuff that matters.

A comment on WhatsApp gives users an ultimatum: Share data with Facebook or stop using app. Parent comment

Re:WhatsApp gives users an ultimatum: Share data with Facebo... by dan-robertson on Friday January 08, 2021 @09:24AM (#25684980)
It is true that messages would be deniable if they weren’t authenticated. The design of signal’s protocol is such that messages are authenticated but deniable: it is possible for the recipient to determine that the message was genuine (the information you want to send) but it is not possible for a third party to prove that a message was authentic (the information you don’t want to leak).

See also, this article about doing the same for email: https://blog.cryptographyengineering.com/2020/11/16/ok-googl...

[ Parent | on HN ]
Re:WhatsApp gives users an ultimatum: Share data with Facebo... by h_anna_h on Friday January 08, 2021 @12:34PM (#25687234)
> The design of signal’s protocol is such that messages are authenticated but deniable: it is possible for the recipient to determine that the message was genuine

Via the use of MACs, yes. I never said otherwise. What I said before still holds, as the recipient you can't prove to others that you indeed received a message by a certain someone rather than forged it yourself to incriminate them.

> See also, this article about doing the same for email: https://blog.cryptographyengineering.com/2020/11/16/ok-googl...

The "Marisa" person in the comments is a friend of mine from IRC and I agree 100% with what she said.

[ Parent | on HN ]