I guess you could switch keycaps at a much lower cost, depending on your keyboard model. If those are blank, randomly shuffling them around might be enough as w

I guess you could switch keycaps at a much lower cost, depending on your keyboard model. If those are blank, randomly shuffling them around might be enough as well (if you can do without the new keyboard, and don't think that an attacker would look at the keyswitches wear. This is also something I see quite often on mobile phones with a pin/pattern unlock: you can often infer the pin from the wear pattern, or the grease marks on the screen if the phone was used recently. My keycap wear pattern more or less mirrors the letter frequency in the languages I write.