Towards a Dependable 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, using mechanisms like replication and transactions. Others have put the emphasis on security, with mechanisms like access control and cryptography. However, many practical applications in the Internet require both these dimensions. This paper describes how a set of commercial off-the-shelf (COTS) tuple spaces can be used to implement a dependable (distributed) tuple space. This tuple space 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