Securing intra-communication in 6LoWPAN: A PKI integrated scheme

6LoWPAN standard enables efficient integration of low power wireless networks with IPv6. However the security requirements of 6LoWPANs are high due to undefined deployment scenarios and constrained capabilities of sensor nodes. A number of schemes have been devised for secure communication over the Internet, PKI being the most widely used of them. It provides authentication, non-repudiation, confidentiality and integrity. PKI does not qualify for use in 6LoWPAN as it is not streamlined for these networks and creates a communication and processing overhead which cannot be borne by a simple wireless sensor node. We provide a scheme to integrate PKI and 6LoWPAN by essentially delegating a major portion of key management activity to the edge routers (gateway) of the LoWPAN and limiting the involvement of the end nodes to minimum communication with the edge router. The edge router maintains a Local Key Database (LKDB) by remaining in constant contact with the certification authority (CA) server and oversees all related keying functions in the LoWPAN. A request packet format and algorithm to acquire keys of the destination from edge router is proposed. Performance evaluation of the proposed scheme using a protocol analyzer indicated a time and increased packet count tradeoff for the enhanced level of security. An increase in packet payload during evaluation led to a significant increase in transmitted message count. The proposed scheme did not alter the nature of the packets transmitted and performed well at scalable loads.