Sharing confidential information in distributed systems is often a necessity in the context of many applications, however, it opens the problem of controlling information sharing even among trusted parties. In this paper, we present a formal model in which dissemination of information, in particular information forwarding, is not allowed. Namely, we introduce a fragment of the π-calculus where forwarding of channels is disabled directly at the level of the syntax. This is the only difference with respect to the π-calculus, i.e., that channels that are received cannot be forwarded later on. Apart from the presentation of the language, we also address a preliminary investigation in the behavioral theory of the model. Furthermore, by means of examples, we give an idea of how some privacy notions already studied in the past, such as group creation and name hiding, can be represented in our language, in contrast with previous approaches that required additional language constructs. Finally, we present an encoding of the (sum-free) π-calculus in our calculus and prove operational correspondence. Our encoding allows to put focus on a notion of name ownership that arises in the process model, by confining the name sending capability to well-determined processes which may be of use for security purposes but also for other resource control properties.

在许多应用程序中，在分布式系统中共享机密信息通常是必需的，但是，这带来了即使在受信任的各方之间也控制信息共享的问题。在本文中，我们提出了一种形式化的模型，其中不允许传播信息，尤其是信息转发。即，我们引入π-演算的一个片段，其中直接在语法级别禁用通道转发。这是关于π的唯一区别-演算，即接收到的信道以后不能转发。除了语言的介绍外，我们还对模型的行为理论进行了初步研究。此外，通过示例，我们给出了一个想法，即与过去需要其他语言构造的方法相比，过去已经研究过的一些隐私概念（例如组创建和名称隐藏）如何可以用我们的语言表示。最后，我们给出（无和）π的编码-演算中的演算，并证明操作上的对应关系。我们的编码通过将名称发送功能限制在确定的流程中来集中关注流程模型中出现的名称所有权概念，该流程可以用于安全目的，也可以用于其他资源控制属性。