The principle that only the parties to a contract, including its designated arbitrators, need to have knowledge of or control over the contents and performance of that contract. Privity as an objective of smart contract is a generalization of the legal principle of privity. It formalizes the tradition of „it’s none of your business“. Attacks against privity are epitomized by Eve the eavesdropper, a passive observer of contents or performance, and malicious vandal Mallet, who actively interferes with performance or steals value. Privacy and confidentiality, or protecting the value of information about a contract, its parties, and its performance from Eve, is thus subsumed under privity. Privity often comes into conflict with observability and verifiability.