A secure cryptographic token interface
Christian Cachin, Nishanth Chandran
CSF 2009
A group of mutually trusting clients outsources a computation to a remote server, which they do not fully trust and that may be subject to attacks. The clients do not communicate with each other and would like to verify the correctness of the remote computation and the consistency of the server's responses. This paper presents the Conflict-free Operation verification Protocol (COP) that ensures linearizability when the server is correct and preserves fork-linearizability otherwise. Clients that observe each other's operations are consistent and their operations are linearizable. If the server forks two clients by hiding an operation, however, they never again see operations of each other. COP is wait-free in the sense that when executed with a correct server, non-conflicting operations can run without waiting for other clients. The paper gives a precise model for the guarantees of COP and includes a formal analysis that these are achieved.
Christian Cachin, Nishanth Chandran
CSF 2009
Marcus Brandenburger, Christian Cachin, et al.
DSN 2017
Christian Cachin, Klaus Kursawe, et al.
CCS 2002
Christian Cachin
Information and Computation