We introduce a new method of achieving intrusion-resilience in the cryptographic protocols. More precisely we show how to preserve security of such protocols, even if a malicious program (e.g. a virus) was installed on a computer of an honest user (and it was later removed). The security of our protocols relies on the assumption that the amount of data that the adversary can transfer from the infected machine is limited (however, we allow the adversary to perform any efficient computation on user’s private data, before deciding on what to transfer). We focus on two cryptographic tasks, namely: session-key generation and entity authentication. Our method is based on the results from the Bounded-Storage Model.