Design And Implementation Of A Key Management Scheme For Automatic Gas Meter Reading System Based On WSN

WSN (Wireless Sensor Networks)is a burgeoning wireless network integrated with sensor technology, which has a great potential in various applications. With the rapid development of sensor technology, WSN has made great progress. Besides, the corresponding techniques have been improved from simplex forms to integration and networking forms. Automatic Gas Meter Reading System has replaced the old form of Gas Meter Reading and also has an extensive applied prospect, which makes the WSN combined with Gas Meter Reading System. But the data that Automatic Gas Meter Reading System Based on WSN is confidential, so it is very valuable to research the security of network based on WSN.There are some deficiencies which are not fit for the Automatic Gas Meter Reading System in the key management scheme:KDC(key distribution center):Network size is limited by the capability of base station, the communication overhead of key establishment is too large. Due to the need of large-scale of Gas Meter terminal nodes, the KDC scheme is not suitable. In addition to calculating the reply messages, it also needs to do the encryption and decryption operations.EG(Eschenauer and Gligo):the key connectivity is uncertain. With the enlargement of the network, the senor nodes have to keep more keys. Due to the need of large-scale of Gas Meter terminal nodes, the EG scheme is not suitable for the Automatic Gas Meter Reading System. Once some nodes are compromised, the influence on other nodes will be very tremendous. Resilience is not good and the keys of the compromised nodes can still be used to decrypt the message transferred in WSN.LEAP(Localized Encryption and Authentication Protocol):with good resilience but also bad scalability. Computational cost and communication cost are great. It is increasing of number of Gas Meter terminal nodes, and it is no synchronous for Gas Meter terminal nodes in the process of joining the net. LEAP can not make sure that the new node can be joined the net after the net has been built.KMS-AGMR (A Key Management Scheme for Automatic Gas Meter Reading System) is a key management scheme, it is based on the attribute and specific application of Gas Meter Reading System, which optimizes the security level of Automatic Gas Meter Reading as much as possible. Based on the specific application of Gas-Meter Reading System, two kinds of keys are designed as followed:Pre-distribution Key:Every node has a unique key which is only identified by the base station, and it is related to the node ID. This key is pre-loaded into each node prior to its deployment. Pre-distribution Key KID is used for communication with other nodes before the pair-wise key is built, which uniqueness insure the good security performance. The Pre-distribution Key would be invalid after the pair-wise key is built.Pair-wise Key:Every node shares a pair-wise key with its father node or child node, whose size is 16 bytes. This key is used for communication with two neighbor nodes. During the communication, the message is uploading or downloading. Pair-wise Key is different between two different nodes. The pair-wise key support for the key updating.KMS-AGMR supports for the key updating of in-network nodes, and also guarantees the forward and backward secrecy of key management. Pre-distribution Key meets the security of key establishment and distribution phase. The establishment and updating of Pair-wise Key improve the security level of wireless sensor network and also guarantee the security and reliability of network.KMS-AGMR, which meets the attribute and specific application of Automatic Gas Meter Reading System, is based on TinyOS and is implemented by sensor node (MSP430 chips and CC2420 RF). This scheme is verified in the practical use through the establishment of network key, the update of network key and the discard of network key. In the experiments, the pair-wise key is built through the process joining the network, and application sever send updating parameters periodically in order to update pair-wise key. The node in-network could communicate with other nodes by the pair-wise key. The kind of key improves the level of security and also insures that KMS-AGMR is appropriate for Automatic Gas Meter Reading System based on WSN. Key management scheme which is used in WSN should meet the following indicators: scalability, key connectivity, resilience and so on. Based on the analysis, KMS-AGMR is coincident. We analyze the security of KMS-AGMR under various attack tests and the results show that KMS-AGMR could defend against many sophisticated attacks such as HELLO Flood attack, Message resend, Sybil attack, Wormhole attack. A prototype implementation of KMS-AGMR in a wireless sensor network tested is also reported.