If the key is only held by the doe then how are you ever going to get that deposit? Bring your trash to them? If not then everyone needs to have access, which means no encryption. One could of course feasibly leave out who bought the thing. To prevent fraud though you would probably have to save what the thing is (otherwise someone will just produce trash in China with valid token IDs from the database just to get the deposit) and having a database of that is in it self a very bad thing for businesses at least. You don’t want your competitors to know exactly how much you are selling, otherwise you will definitely get bought out at your lowest point.
Maintaining such a database would be a nightmare too, and all that just to make sure the tokens do fall in value with inflation? I don’t see the point really. Either fix the value for a couple of years, or let it rise through inflation that would incentivize the collection of old garbage at least.
Tlaloc_Temporal