Energy-efficient Replica Voting Mechanisms for Secure Real-time Embedded Systems

The paper employs majority voting among replica processes to move a correct data from the environment to the end-user entity in a secure real-time application setting. The replicas may be wireless computation nodes deployed in a power-constrained environment, and the data may be quite large in size with nonnumeric and non-exact contents (e.g., imaging devices in a geographic terrain). The voting protocol is made energy-efficient by reducing the amount of data processing and network-level message exchanges required in delivering a data to the user. Our optimization takes into account: i) processing cycles expended in comparing data, ii) amount of replica data movement required, and iii) number of control messages generated. We consider two types of voting protocol: a ’centralized ’ scheme where replica data are collected at a secure power-abundant site to carry out the data comparisons for voting; and a ’decentralized ’ scheme where each replica compares its locally computed data with a candidate data to send its consent/dissent message to a central vote collating site. The paper develops a performance model that considers the tradeoffs (i)-(iii) to determine the energy consumption levels in the centralized and decentralized voting schemes. Our model allows the voting apparatus to select an energyoptipmal scheme, given the timeliness parameters and the network and processing bandwidths