关键词: 延迟容忍网络（DTN）, 密钥管理, 安全, 身份认证, 卫星及便携终端, 混合网络, 内容分发

Abstract: Because the existing key management schemes are not applicable, a new key management scheme is proposed for the special DTN environment in the content delivery system for remote area which consists of satellite and portable terminal hybrid network. In the scheme, the satellite network receiving server in the content delivery system issues the digital identity cards for users. A user can generate his public-private key pair by himself, then he binds it with the digital identity card to produce the blind digital identity card which can be used for authentication and public key acquisition. By adding the lifetime of the key in the authentication data, the key of a user can be periodically updated and the replay attack for the public key acquisition can be prevented. This paper analyses the security of the scheme and compares it with other schemes. The analysis shows that the scheme meets the security requirements, which is suitable for the special DTN of the satellite and portable terminal hybrid network content delivery system.

Key words: Delay Tolerant Network（DTN）, key management, security, authentication, satellite and portable terminal, hybrid network, content delivery