Design and Implementation of an Intrusion-Tolerant Tuple Space

The tuple space coordination model is one of the most interesting communication models for open distributed systems due to its space and time decoupling and its synchronization power. Several works have tried to improve the dependability of tuple spaces. Some have made tuple spaces fault-tolerant while others have focused on security. However, many practical applications in the Internet require both these dimensions. This paper describes the design and implementation of DEPSPACE, a dependable communication infrastructure based on the tuple space coordination model. DEPSPACE is dependable in a strong sense of the word: it is secure, fault-tolerant and intrusion-tolerant, i.e. it behaves as expected even if some of the machines that implement it are successfully attacked. Moreover, it is a policy-enforced augmented tuple space, a shared memory object that we have recently proven to be universal, i.e., capable of implementing any other shared memory object.