Paper 2015/949

Private Processing of Outsourced Network Functions: Feasibility and Constructions

Luca Melis, Hassan Jameel Asghar, Emiliano De Cristofaro, and Mohamed Ali Kaafar


Aiming to reduce the cost and complexity of maintaining networking infrastructures, organizations are increasingly outsourcing their network functions (e.g., firewalls, traffic shapers and intrusion detection systems) to the cloud, and a number of industrial players have started to offer network function virtualization (NFV)-based solutions. Alas, outsourcing network functions in its current setting implies that sensitive network policies, such as firewall rules, are revealed to the cloud provider. In this paper, we investigate the use of cryptographic primitives for processing outsourced network functions, so that the provider does not learn any sensitive information. More specifically, we present a cryptographic treatment of privacy-preserving outsourcing of network functions, introducing security definitions as well as an abstract model of generic network functions, and then propose a few instantiations using partial homomorphic encryption and public-key encryption with keyword search. We include a proof-of-concept implementation of our constructions and show that network functions can be privately processed by an untrusted cloud provider in a few milliseconds.

Note: Typo in the name of the third author.

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Publication info
Published elsewhere. Major revision. A preliminary version of this paper appears in the 1st ACM International Workshop on Security in Software Defined Networks & Network Function Virtualization. This is the full version.
privacy in network function evaluationhomomorphic encryptionsearchable encryptionsoftware defined networking
Contact author(s)
hassan jameel @ gmail com
2016-01-25: last of 2 revisions
2015-09-30: received
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      author = {Luca Melis and Hassan Jameel Asghar and Emiliano De Cristofaro and Mohamed Ali Kaafar},
      title = {Private Processing of Outsourced Network Functions: Feasibility and Constructions},
      howpublished = {Cryptology ePrint Archive, Paper 2015/949},
      year = {2015},
      doi = {10.1145/2876019.2876021},
      note = {\url{}},
      url = {}
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