Digital Social Contracts: A Foundation for an Egalitarian and Just Digital Society

Almost two centuries ago Pierre-Joseph Proudhon proposed social contracts -- voluntary agreements among free people -- as a foundation from which an egalitarian and just society can emerge. A \emph{digital social contract} is the novel incarnation of this concept for the digital age: a voluntary agreement between people that is specified, undertaken, and fulfilled in the digital realm. It embodies the notion of "code-is-law" in its purest form, in that a digital social contract is in fact a program -- code in a social contracts programming language, which specifies the digital actions parties to the social contract may take; and there is no outside jurisdiction to such a contract -- the parties to the contract are entrusted, equally, with the task of ensuring that each party abides by the contract. Parties to a social contract are identified via their public keys, and the one and only type of action a party to a digital social contract may take is a "crypto-speech act" -- signing an utterance with her private key and sending it to the other parties to the contract. Here, we present a formal definition of a digital social contracts as a transition system that specifies a system of automata, one automaton per party, which communicate asynchronously via crypto-speech acts, where the output of each automaton is the input of all the other automata. We outline an abstract design for a social contracts programming language, whose rules specify social contract transitions, and show, via programming examples, that key application areas, including social groups; communities of hosts and tourists; egalitarian currency networks; and democratic community governance, can all be expressed elegantly and efficiently as digital social contracts. Social contracts may include anonymous agents, whose code is executed jointly by all parties to the contract, similarly to so-called "smart contracts".