The invention relates to a reconfigurable scalable intrusion-tolerant network that is interposed between a service requesting client and a protected server to minimize the impact of intrusive events. The apparatus may include a proxy server for receiving the requests from a client and forwarding them to a protected server. Acceptance monitors receive the response from a protected server and apply one or more acceptance tests. A ballot monitor receives the result of the acceptance tests and determines a response to the client. The network may also include an intrusion sensor to detect threats to the network and a reconfigurer to alter the network forwarding scheme. Reconfiguration may include isolating network elements, creating parallel paths, implementing redundant operations, or assessing the validity of responses.