Is privacy just an illusion? The question arises more and more frequently due to the recent outbreak of spying scandals. As it becomes increasingly important protecting our privacy, handling safely our data and internet traffic, it becomes necessary a special encryption method, which on one hand makes impossible to intercept and collect data for a third party or different service providers, on the other hand, however, be able to make operations with them on the encrypted data. This specific method is the homomorphic encryption. One of the possible applications is the Network Functions Virtualization. It addresses the separation of the hardware devices from the network functions and proposes software implementations. The question arises how such features or new services that appear in the future work on encrypted data traffic.
In this thesis, I examine the applicability of homomorhic encryption in the virtual network functions. I define a specific function and I give a possible use-case for it, I have made a piece of software for experimentally analyzing this application: which is able to carry out operations on encrypted images.
The first part of my thesis contains background information of the homomorphic encryption. This is followed by the definition of the specific network function and a use-case for it: in case of instant messaging programs that are capable of group communication, it is possible to change the transmitted and also encrypted images, without the application could access to the specific image. While retaining the protection of privacy this makes possible for those users who have limited internet traffic in their subscription to get the picture in tailor-made size. Then I present the implementation of a software that helps to experimentally analyze the effectiveness of the specified function. The experimental results show that in the tested cases the necessary time to perform the encryption is by far the most, and that this method has huge memory consumption.
All in all, the homomorphic encryption is justified in the world of virtual network functions, but in the future there is a need for a solution that solves the problem of the huge resource requirements.