The application context of our work is a secure storage system. The system consists of a set of servers denoted , and a distinct set of clients accessing them.
Correct servers remain alive and follow their specification.
Throughout the run of our protocols, however, we assume a bound on the number of faulty servers. Clients are assumed to be correct, and each client may communicate with any server over a reliable, authenticated communication channel. That is, a client receives a message from a correct server if and only if sent , and likewise receives from iff sent . Furthermore, we assume a known upper bound on the duration of a round-trip exchange between a client and a correct server, i.e., a client receives a response to message sent to a correct server within at most delay. In our protocols, we need not make any assumption nor employ communication among the servers.