| You are already giving an unclear definition when you use terms like "mining hash power." What rigorous definition can you give for that term? What sort of model of computation are we working with (or is the definition based on information theory?)? For comparison, consider the definition of security used in this recently published paper: http://eprint.iacr.org/2013/443 The definition is long, but very clear. Probabilistic polynomial time Turing machines are used as a model of computation; the adversary is given more power by being allowed to be non-uniform (i.e. the adversary can be a different machine for different security parameters). The security properties are clearly defined in terms of this model of computation, and a construction is given and proved to meet the properties (under certain hardness assumptions). Note that there is no possible way that Bitcoin could meet the security definition given in that paper, because that definition requires the existence of a bank that issues the cash. This is true of previous work on digital cash as well, including the work that preceded Bitcoin. That is why it is necessary to develop a security definition that makes sense for systems like Bitcoin -- digital cash systems in which there is no bank. That is the complaint I have: no satisfactory definition has been given. "This is not part of any proir school of economics, but it's close to common sense, and is strongly supported by the success of bitcoin thus far." Economics often defies common sense, so I would be wary of using common sense as the basis for a currency. |