Secure Network Coding Astgainst Wiretapping Attacks

Network Coding has been proved to improve the throughput and robust of thenetwork and so on. It achieves the multicast rate of network. However, there exist twokinds of adversaries in communication networks using network coding: eavesdroppingand errors. Eavesdropping referring to the adversary aims to get the information aboutthe source message by eavesdropping some selected links. Errors include random errors,erasures, and errors caused by attacks from malicious nodes. In this dissertation, westudy the problem of the wiretapping and error correction, and design some admissiblenetwork coding schemes to conquer them.The main contributions of this dissertation are listed as follows.1. We proposed a network coding scheme with symmestric encryption against fulleavesdropping attacks. The precoding matrix is constructed by the mapping valuescorresponding to the origin message packets. The origin message packets are encodedby the precoding matrix instead of locked coefficients. The overhead of the encryptedmessage is independent of the number of origin packets then improved the networkbandwith.2. A computationally secure against eavesdropping network coding algorithmbased on hash function is presented. In this algorithm, the secret message is used torecursive generating random numbers by hash function. Without wasting bandwith forrandom numbers, we construct an appropriate transform matrix, which is used to hidethe random number. By means of this algorithm, the adversary can obtains noknowledge about what the source has transmitted.3. A universal strongly secure network coding algorithm is presented. The sourcemessage is pre-encoded by using coset coding scheme that uses maximum rank distance(MRD) codes over extension field. Meanwhile, focusing on the intermediate nodes,linear network code over base field is used. The precoding at source node isindependent of the linear network code, and the size of base field is also reduced.4. We consider the secure broadcasting network coding problem over an acyclicnetwork with single source node and two sink nodes. An admissible algorithm ispresented. Given network topology and network codes, different parts of the secretmessage are received by different sink nodes without any information leaking to the adversary. Besides, the sufficient condition for the existence of our algorithm is alsoderived.5. We consider the secure-error correction broadcasting network coding problemover an acyclic network with single source node and two sink nodes. The constructionof admissible nested code for secure-error correction broadcasting is proposed. Thenecessary and sufficient conditions of the admissible nested code are derived. At last,the conjecture proposition of the secure-error correction capacity region of broadcastingnetwork coding is presented.