Waes thu hal!

Yes, Heraklia, the Anglo-Saxons had keys. And I'm guessing (although I may be wrong) that you are right in that the answer to Lucius' riddle is a key to a fellow's house. At any rate, the Anglo-Saxon peoples do seem to have had a rather, ahem, earthy sense of humour and there do seem to be quite a few riddles that use double entendre--that is, they sound as if they are talking about something of a sexual nature when, in reality, the answer to the riddle is some common, everyday object that has nothing to do with sex!

Theodric Scylding