Method for session key generation and updating in a distributed communication network.

摘要

A method is provided which allows a set of servers to maintain a set of keys, shared with a client, in the presence of mobile eavesdroppers that occasionally break into servers and learn the entire contents of their memories. Static and dynamic schemes maintain secret keys common to the user and each of several servers in the presence of a mobile, transient adversary that occasionally breaks into servers in order to gather information on the users' secret keys. The schemes use periodic "refreshments" of every user's private keys. In each round the servers involve in a computation in which each server computes a new private key to be shared with the user, in a way that allows the user to keep track of the changing keys without any communication with the servers. The schemes are very efficient. In particular, a user has to interact only with one server in order to obtain a session key. The user may choose the server with whom it wants to interact. The method may be used to securely generate random numbers (i.e., using the keys as random numbers).