Paper 2007/056

Enforcing Semantic Integrity on Untrusted Clients in Networked Virtual Environments

Somesh Jha, Stefan Katzenbeisser, Christian Schallhart, Helmut Veith, and Stephen Chenney


During the last years, large-scale simulations of realistic physical environments which support the interaction of multiple participants over the Internet have become increasingly available and economically viable, most notably in the computer gaming industry. Such systems, commonly called networked virtual environments (NVEs), are usually based on a client-server architecture where for performance reasons and bandwidth restrictions, the simulation is partially delegated to the clients. This inevitable architectural choice renders the simulation vulnerable to attacks against the semantic integrity of the simulation: malicious clients may attempt to compromise the physical and logical rules governing the simulation, or to alter the causality of events a posteriori. In this paper, we initiate the systematic study of semantic integrity in NVEs from a security point of view. We argue that naive policies to enforce semantic integrity involve intolerable network load, and are therefore not practically feasible. We present a new provably secure semantic integrity protocol based on cryptographic primitives which enables the server system to audit the local computations of the clients on demand. Our approach facilitates low network and CPU load, incurs reasonable engineering overhead, and maximally decouples the auditing process from the soft real time constraints of the simulation.

Available format(s)
Publication info
Published elsewhere. An extended abstract of this paper appears at the IEEE Symposium on Security and Privacy, 2007
protocolsaudit trails
Contact author(s)
skatzenbeisser @ acm org
2007-02-20: received
Short URL
Creative Commons Attribution


      author = {Somesh Jha and Stefan Katzenbeisser and Christian Schallhart and Helmut Veith and Stephen Chenney},
      title = {Enforcing Semantic Integrity on Untrusted Clients in Networked Virtual Environments},
      howpublished = {Cryptology ePrint Archive, Paper 2007/056},
      year = {2007},
      note = {\url{}},
      url = {}
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