Pro-active message's delay tolerant networks (DTNs) are based on the usage of mobile code to obtain messages that contain their own routing code. This architecture allows applications to use the same network in different ways. The keystone of this type of heterogeneous network is a collection of contextual and application-related information that it is stored in every node and accessed by the messages' routing code. Access to that information must be protected in order to make the whole architecture feasible; the operation of the network has to be secure, and attacks of information poisoning have to be avoided. We propose an identity-based access control system for pro-active message's DTN based on tools that are available in DTN networks, like symmetric key encryption and hashes. Our system grants confidentiality and integrity to the contextual information and solves the question of messages needing to use distributed information stored in nodes to route properly. The proof of concept of identity-based access control in a certain kind of application demonstrates the feasibility of the proposal. The comparison between our proposal and other access control systems shows that identity-based access control is the only system that fits well with the special characteristics of pro-active message's DTN. Copyright (c) 2016 John Wiley & Sons, Ltd.