[jrub]

Legitimate question:

The whole "delete when you're done' practice is a pretty common tenant to secure communication. However, there are plenty of cases where having that historical data is really useful. After all, computers are excellent at storing archival data, and being able to search and reference that archive has saved me more times than I can count.

What practice, then, can you employ to maintain a secure archive of your messages for future reference? Is this something that is considered rude, or even dangerous and reckless, given that the mere existence of the archive introduces an attack vector, thereby compromising the effectiveness of encrypting the messages at all?

I understand that there are a lot of trade offs and sacrifices to be made in the name of security, but is maintaining a message archive one of those sacrifices that is expected to be made by all parties? Or is this one of those points that can't be covered with a blanket statement, and the retention policy is pretty much dependent 100% on the sensitivity of the content?

[grugq]

Yes.

[grugq]

To elaborate, the security precautions you take are entirely dependent on the threat you face (or believe you face). If you're Dread Pirate Roberts, creating a detailed diary of you criminal activities is a terrible idea [1]. If you're a 13 yr old girl, creating a detailed day by day diary is probably not a life threatening decision.

You should take the precautions appropriate for your threat model and risk appetite. I suggest deleting correspondence after a set period of time. I know people that do a yearly purge of all their sensitive mail for the previous year in January.

If you are encrypting for the sake of encrypting, as some people do (see: cover traffic), then you can keep archives of your mail because you face no negative outcome if your archive is compromised. There is no downside, so go for it.

[1] https://www.youtube.com/watch?v=pBdGOrcUEg8