Group Key Management for Secure Multicasting in Remote Software Upload to Future Vehicles 2006-01-1584

In future, updating various software modules in vehicles on a regular basis will be required for various reasons such as update functionalities in the existing system, add new functionalities, remove software bugs, update navigation map etc. For updating software to a large number of vehicles, remote updating using mobile multicasting would be the most efficient and economic than unicast updating in service station. However, the security requirement of multicast communication, i.e., confidentiality and integrity of the information transmitted and authenticity of the group members, is challenging. In this paper, we investigate issues in designing key management architectures for secure multicast network, particularly for remote software update in future vehicles. Vehicular software distribution network is considered as wireless network where vehicles are connected to the software distributors through base stations. Since the network consists of vehicles and base stations, the network dynamics is characterized by quasi-permanent mobility, high speed and frequent hand-off. High mobility and frequent hand-off increase the complexity of dynamic group membership which results in increase complexity in key generation and distribution. However, unlike the other mobile hosts such as PDA, vehicles provide sufficient battery, computational power and memory which allow performing complex cryptographic algorithm. Taking these things into consideration, we propose to use decentralized key management technique to generate and distribute multicast session key to the group members. Consequently, we evaluate our proposed architecture based on key distribution efficiency, re-keying efficiency, computational complexity, key storage requirement and scalability. From our analysis, it is found that the set-up and re-keying time of the proposed mechanism is in the range of few milliseconds while it provides confidentiality, authenticity and data integrity.