Padding and fragmentation for masking packet length statistics

Abstract

We aim at understanding if and how complex it is to obfuscate traffic features exploited by statistical traffic flow classification tools. We address packet length masking and define perfect masking as an optimization problem, aiming at minimizing overhead. An explicit efficient algorithm is given to compute the optimum masking sequence. Numerical results are provided, based on measured traffic traces. We find that fragmenting requires about the same overhead as padding does. © 2012 Springer-Verlag