The Design And Security Research Of6Lowpan Embedded Gateway

As an emerging network, Wireless Sensor Network (WSN) has developed rapidly and received widespread attention. It extends people’s ability for getting physical information, and has broad application prospects. IEEE802.15.4standard is established for Low-Power Wireless Personal Area Network (LoWPAN). It defines the PHY and MAC layer with low power, rate and cost. Because of limiting factors in LoWPAN, applying IP technology to LoWPAN was considered to be unrealistic.6LoWPAN (IPv6over LoWPAN), proposed by IETF, achieves a seamless connection of IPv6and IEEE802.15.4networks.With the application of wireless sensor technology in various fields, the security must be considered in network design. The open network deployment of6LoWPAN makes devices vulnerable to the physical destruction from enemy, and completely exposed radio channel is also a target of attacks. Besides basic secure requirements of general networks, the implement of6LoWPAN security must consider its own characteristics, which restrict application of many complex and mature security protocols and algorithms in6LoWPAN network.Combining the application of IPv6in LoWPAN and6LoWPAN security, this paper proposes an embedded secure gateway based on6LoWPAN, and researches its network security issues. The main content is as follows:This paper begins with a brief analysis of IEEE802.15.4and6LoWPAN network protocol stack. Then, we propose the design of dual stack of gateway. Three modules are defined in the gateway to complete query conversion, address mapping and encryption/decryption.802.15.4devices have two types of MAC addresses:16-bit short addresses and IEEE EUI-64extended addresses. The length of packets transmitted in802.15.4is smaller than that defined in IPv6, which needs the adaptation layer to implement fragmentation and reassembly for oversize packets, and adopt header compression to improve utilization of slice. So the gateway adds an address mapping table to achieve rapid conversion of16-bit short addresses and IPv6 address, and nodes in6LoWPAN are all communicated with short addresses, which improves slice utilization and speeds up handling packets on nodes. In addition, the gateway can also store data periodically sent by nodes to meet users’query for historical data.Then, we analyze the security of IEEE802.15.4, IPv6and6LoWPAN, and researches network security issues of the embedded gateway. Based on analysis and comparison of several common encryption algorithms, RC5proves to be simple and efficient. SNEP, which is a security protocol for WSN with low communication overhead, only describes the process of security implementation without appointing specific algorithms. In this paper, RC5and CBC-MAC algorithms are adopted for implementation of SNEP. In order to ensure secure access to the gateway for remote users, a GoAhead Web Server which provides multi-user hierarchical access, is used to prevent unauthorized users.Finally, the gateway is implemented with UP_CUP6410experimental platform. At present, there is not shared source code of6LoWPAN, so job on coding is completed independently.6LoWPAN protocol is transplanted in NS2. Performance and security of the gateway is analyzed through simulation. The experimental results show that the gateway not only achieves6LoWPAN-IPv6Network Interconnection, but also introduces SNEP protocol to guarantee secure communication in6LoWPAN, so performance and security of the gateway are well balanced.