I'm not sure whether we want to use Enter here. The fix is trivial, but there are quite a few dialog showing a certificate list where pressing Enter has a different effect, e.g. the server lookup does Import on Enter and the details dialog does Update (even if the certifications tab is shown where double click opens the details of the certifying key). Using Enter as shortcut might have been a bad idea in general because it doesn't work everywhere.

In the "Edit Group" dialog I'm wondering if it wouldn't be much more convenient if Enter moved the key to the other list. And I've been pondering the same for double click, by the way. The primary action in this dialog is to move keys from the available list to the group list and occasionally vice-versa. Consequently, this action should be as easy as possible. Using Enter for keyboard users and double click for mouse users seems like an obvious choice. (Most mouse users will likely also expect drag&drop which also doesn't work but that's yet another story.)

In T8424#223095, @ikloecker wrote:

In the "Edit Group" dialog I'm wondering if it wouldn't be much more convenient if Enter moved the key to the other list. And I've been pondering the same for double click, by the way.

Agreed, this would be my expectation.

Then what about just adding a new context menu item: "Show Certificate Details" to make it accessible?