Using a centralized blind currency mixing scheme can help solve this some. Silk Road could implement 'Silk Road Coins' (SRC) based off one of the many papers on centralized blind tokens. Then Alice can exchange 100 Bitcoins for 100 SRC. When Alice places an order from Bob she would pay him with SRC which he can redeem for bitcoins from the SR server, and because of the blinding algorithm the admin of SR will not be able to tell that Bob got the SRC from Alice, only from someone who has enough SRC to pay for the order. Since SRC could be reblinded and spent anonymously, they wouldn't even necessarily have to know who has how many SRC at any given time. A vendor could stockpile SRC for a while before exchanging them for Bitcoins, and then the admins wont even know the amount of transactions the vendor made to get those SRC since the SRC made from many deals would be mixed together into one arbitrarily sized pot. They could still collect their fee simply by charging a 5% fee for the exchanging between SRC and BTC. As far as the product listings go, that is a little bit more tricky. It is pretty much going to be impossible to hide the products from the site admins while making them available to everybody else, because as was previously mentioned the admins could just make accounts themselves. It will also be hard to separate the listings from the vendor offering them without removing the ability to do reviews on vendors. You could break the review system apart into reviews on single product listings rather than reviews on vendors with many listings, but that will make scamming easier (also you would need open anonymous registration for all vendors and customers, so no more charging for vendor accounts. Perhaps you could charge a smaller fee for individual listings, payable with SRC). Many of the things you are mentioning could be done, but not with a centralized design. So with a centralized design I think you can have a 'taxed' market where transaction details (who is paying who for what) are hidden from the site admin, but the product listings (what is available) would need to be publicly available. Maybe if you clarify the specific requirements of what type of system you are looking for, I will be able to think of a way to do it. Right now I am a little shaky on the details of exactly what criteria you want this market to meet. edit: actually if anybody can anonymously exchange BTC for SRC, the site admin wont even need to know who has how many SRC at all, vendors or customers.