Vulnerability of MRD-Code-based Universal Secure Network Coding against Stronger Eavesdroppers

Abstract

Silva et al. proposed a universal secure network coding scheme based on MRD codes, which can be applied to any underlying network code. This paper considers a stronger eavesdropping model where the eavesdroppers possess the ability to re-select the tapping links during the transmission. We give a proof for the impossibility of attaining universal security against such adversaries using Silva et al.'s code for all choices of code parameters, even with restricted number of tapped links. We also consider the cases with restricted tapping duration and derive some conditions for this code to be secure.Comment: 7 pages, no figure, ieice.cls, a part of this paper was presented in 2010 IEEE International Symposium on Information Theory. The proofs in V2 became more readable than V1, but the results unchange