Quorum consensus algorithms for secure and reliable data

The authors address the issue of maintaining security in a fault-tolerant replicated database. They present a data-management protocol that integrates the information-dispersal algorithm (for security) and the quorum-consensus algorithm (for reliability). Although this protocol provides the desired level of security, it does not achieve the same level of availability for both read and write operations as the quorum-consensus algorithm. By integrating a log-based propagation mechanism with their protocol, the authors are able to achieve the same level of availability for both read and write operations as other quorum-consensus protocols, while maintaining the desired level of security