Relaxing Environmental Security: Monitored Functionalities and Client-Server Computation

  • Manoj Prabhakaran
  • Amit Sahai
Part of the Lecture Notes in Computer Science book series (LNCS, volume 3378)


Definition of security under the framework of Environmental Security (a.k.a Network-Aware Security or Universally Composable Security) typically requires “extractability” of the private inputs of parties running a protocol. Formalizing concepts that appeared in an earlier work [19], we introduce a framework of “Monitored Functionalities,” which allows us to avoid such a requirement from the security definition, while still providing very strong composition properties. We also consider a specialization of the Environmental Security framework by designating one party as a “server” and all other parties as clients. Both these contributions in the work are aimed at being able to provide weaker Environmental Security guarantees to simpler protocols. We illustrate the usability of the Monitored Functionalities framework by providing much simpler protocols in the plain model than in [19] for some limited functionalities in the server-client model.


Hash Function Hamiltonian Cycle Environmental Security Probabilistic Polynomial Time Static Adversary 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2005

Authors and Affiliations

  • Manoj Prabhakaran
    • 1
  • Amit Sahai
    • 1
  1. 1.Princeton University and UCLA 

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