Information dependability in distributed systems: The dependable distributed storage system

Abstract

In distributed infrastructures data are usually scattered among different nodes and thus accessible by several users. It is therefore necessary to provide mechanisms and tools for managing the information, ensuring the access exclusively to authorized users avoiding malicious ones. Furthermore, satisfactory performance and adequate fault tolerance have to be provided while addressing information confidentiality, availability and integrity issues. In this paper we face the problem of data dependability in distributed system, proposing a redundant lightweight cryptography algorithm combining symmetric and asymmetric cryptography approaches. The proposed algorithm, named dependable distributed storage system (D²S²), has been implemented on top of the Grid gLite middleware file access and replica management libraries, as a file system service with cryptography capability, redundancy management and POSIX interface. To demonstrate the effectiveness and the applicability of the D²S² gLite implementation, performance and reliability of its operations have been evaluated and compared to those of existing solutions. The tests have been performed on real applications to provide a complete overview of the D²S² implementation. The results thus obtained demonstrate the effectiveness of the D²S² implementation also compared to existing solutions and former implementations.