Throughout their history, puts and calls [1] on common stock have been criticized as mere gambling opportunities. Recently, the creation of listed options on the Chicago Board Options Exchange, the American Stock Exchange and three regional exchanges in the United States, has given new respectability to options as investment vehicles. By year-end 1977, listed options to 217 common stocks were a...

We present an interesting new protocol where participants in a securities exchange may submit cryptographically encrypted rules directly to an exchange rather than orders to buy and sell. We define this in two parts: a secure, partially trusted computer that runs the exchange and proves its actions correct, and a set of participants who define the rules and submit them to the exchange. At each ...