it's too easy for a user to lose their E2EE keys if their server logs out their device

element-hq / element-meta

Shared/meta documentation and project artefacts for Element clients

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it's too easy for a user to lose their E2EE keys if their server logs out their device #1868

Open ara4n opened 3 years ago

ara4n commented 3 years ago

We have a nasty paradox in our megolm key management.

Sometimes a user will want to log out a mislaid device and consciously ask it to delete its E2EE keys for safety
However, sometimes a server will just disappear (e.g. during a bad outage), which might trigger the client to log out, deleting the only copy of that user's E2EE keys.

Therefore we need to make sure that we never spontaneously delete the local E2EE keys unless the server is explicitly issuing a hard logout on the device, and we also need to make sure the user has the ability to export their E2EE keys even if the server has gone missing (which I think might work already?)

turt2live commented 3 years ago

we should already have that feature (not obliterating keys when the server dies), but if it happens then a rageshake would be good. We also have a soft logout concept that servers can use to re-auth if that's all they need.

jryans commented 3 years ago

sometimes a server will just disappear (e.g. during a bad outage), which might trigger the client to log out

Have you observed that actually happening in Element Web...? I am not aware of us doing this, and it sounds like a bug to fix if it does happen...

RalfJung commented 1 year ago

https://github.com/vector-im/element-web/issues/3611 got closed as a duplicate of this. The issue isn't just about server outages. The issue is that users don't realize that clicking "log out" means "delete my private keys". So the current UI makes it really easy for someone to accidentally delete their keys. I'm sufficiently well-versed with public key crypto to be able to use GPG, and yet I managed to lock myself out of my matrix keys within days. This is a sign of very misleading UI.