The Research Of Identity-based Online/Offline Encryotion Algorithm

The wireless sensor network consists of numbers of sensor nodes which form the network byself-organization, data encryption is the essential link to protect data transmission security. Sincesensor nodes are embedded devices with limited power energy and computation ability, it proposeshigher requirements to computational complexity of encryption algorithm. This paper focus ondesigning a kind of encryption algorithm that could save computational overhead in sendor nodesand guarantee security in network at the same time, so this topic has theoretical significance andpractical value.This paper proposes two new Identity-Based Online/Offline Encryption algorithms based on theanalysis of Waters-IBE and Gentry-IBE. The main idea of the new algorithm is that the encryptprocess is divided to two phases–online and offline phases. In the offline stage, all heavycomputation can be done by PKG or base station prior to knowing the message and the recipient,then generate an offline ciphertext and send to sensor nodes which needs to send messages. Onlinestage can be conducted efficiently with some light computation to encrypt a message using offlineciphertext directly once the message and the recipient’s identity become available. Spliting theencrypt process into two parts made it more efficient and rapid for online encryption, therefore it issuitable for wireless sensor network with limited resources.What’s more, this paper also improves Distributed Identity-Based Encryption and proposesDistributed Identity-Based Online/Offline Encryption aiming at distributed systems, it could enhanceoperating efficiency in sensor nodes of distributed system.This paper not only puts forward the specific implementation of three Identity-BasedOnline/Offline Encryption, but also makes simulations and security proving, and analyse simulationresults, algorithm performance and security of these new algorithms. The simulation results showthat the new algorithms in this paper reduces computation and computing time in sensor nodeseffectively without lower the security compared to the original algorithms.In a word, the algorithms proposed by this paper are more suitable for wireless sensor networkeither from theory or realization aspects.