{writeup; http://bit.ly/AZcrypto} There are two different questions: How to apply Islamic rules to crypto currency within the Capitalist society in which we live? This is entirely different from how to construct an Islamic society, and what would the role of crypto currency be within such a society. I am concerned in this talk with the second question. An Islamic society is based on principles of generosity, cooperation and social responsibility - these are diametrically opposed to greed, competition, and individualism which form the basis of capitalist society. Whereas money is central to a capitalist society and is able to purchase lives of human beings, money plays only a secondary role in an Islamic society. Within money categories, crypto is a privately created money which would be either illegal or useless in a Islamic society. Various kinds of community created money, backed by government guarantees, and used for enhancing lives and welfare of people, would be permissible - It may be possible to adapt crypto for this use, but this would require rethinking and re-engineering.