[nerdponx]

I find this weird and almost the opposite of what I would want.

I would want a system where I cannot repudiate messages that I sent, but I must repudiate (i.e. cannot claim authorship of) messages that I did not send.

As far as I understand, isn't that how asymmetric encryption typically works? What's the advantage of symmetric encryption in this case?

[eru]

See https://en.wikipedia.org/wiki/Off-the-Record_Messaging