> you have kept a perfect record of every conversation you've ever had The other side of this coin is deniability. If you break into my secure location and ste

> you have kept a perfect record of every conversation you've ever had The other side of this coin is deniability. If you break into my secure location and steal my chat logs, but you can't tell which are real and which are fake, you've still got work to do. The Signal protocol has you covered, here. After the fact (ie, as long as you don't watch me receive the message), there is no way to cryptographically prove which of the two participants wrote the message[0]. Thus, it is technically possible to forge a bunch of chat history, or claim that someone else's is forged. Cryptographically, the "spirit of forward secrecy" is secure. That said, this is far out of the reach of the average person. Even if the only evidence is a screenshot, that conversation probably happened. So in practice yes, you've got a point. That's why I think it would really behoove Signal to add a "forge a conversation" feature. Make it trivial for either person to add a message to their local history that looks like it came from any of the participants, at a specific date/time. Now you've got practical deniability, too. [0] https://signal.org/docs/specifications/x3dh/#deniability https://signal.org/docs/specifications/x3dh/#deniability