Secure Transmission Scheme Based On Network Coding

Unlike general routing strategies,network coding(NC)can combine encoding functions with multi-path propagation over a network.This allows network capacity to be achieved to support complex security solutions.Moreover,NC has intrinsic security advantages against passive attacks over traditional routing techniques since the source messages will be divided into multiple packets and sent to the intended receivers in a multi-path way.Linear network coding(LNC)is the most efficient network coding scheme,and the proposal of random linear network coding(RLNC)also further improves the practicability of LNC systems,so the most security research is based on LNC system at present.However,it is difficult for LNC systems to guarantee security when allocating the global coding core of each link.Therefore,when the number of intercepted links is greater than or equal to the source dimension,the security of the system is still difficult to guarantee.This paper proposes a generic unicast secure transmission scheme based on RLNC.Specifically,the destination generates a random matrix upon receiving the request from the source node and then transmits each row vector of this matrix over a link reversely to the source node.Each intermediate node rearranges all received vectors to form a matrix by row,and then post-multiplies its local encoding kernel by this matrix to obtain a new matrix.Similarly,each row vector of the new matrix is reversely transmitted over a link to the source node.This procedure is performed until we have the source node,where the generalized inverse of the received matrix(or part of it)can be used as its local encoding kernel.Hence,the destination node can use the generated matrix(or the corresponding part)to decode the received data packets directly.We also analyze the security to demonstrate that eavesdroppers can recover the source messages only if all wiretapped links exactly constitute a cut set of the network that can “cut”the network.We also demonstrate the utility of the scheme with a simulation.The proposed scheme is also physically implemented,we elaborate the design of routing devices for packets' sending/receiving and coding process of the NC packets.We implemented the proposed scheme based on Linux and using C language.Our software is compatible with traditional routing and classic RLNC scheme.An environment is built for testing the feasibility and security.