Providing Secure Integrity in Peer-to-Peer Oriented Mobile Environments

Providing confidentiality, integrity, and availability is indispensable for secure systems. In particular, almost every commerce application requires that integrity be provided in a secure manner, such that the integrity of data is retained even if the owner of the data is malicious. However, providing secure integrity in mobile environments, where participating nodes and their communication channels are unstable, is not a simple task. This is mainly because of the difficulty of solving the agreement problem securely in these environments due to the unreliability of channels, and the passivity of smartcards that complicates the implementation of distributed protocols among them. In this paper, we propose an optimistic approach to address these problems. This approach introduces an optimistic non-blocking atomic commitment (NBAC) protocol for smartcards to secure reliable agreements, and implements the protocol on a distributed framework for inter-smartcard communication to relax the implementation complexity. Our implementation results show the feasibility of this approach: current smartcards can conduct the protocol in no more than about a half second, which should be enough performance to support commerce transactions, the application most likely to need secure integrity.