Cloud computing is a recent computing model; provides consistent access to wide area distributed resources facing many problems as its usage increases. Enormous loss to both cloud clients as well as cloud service providers happen even with small intrusions. The protection and defense of cloud infrastructure against malicious attacks can be solved by designing 'Intrusion tolerance'. The authors prove the renewal and confidentiality property of sensitive data by utilizing secret sharing and adding a proxy server. Proxy server acts as an intermediate server between the client system and cloud servers; blocks the intruders by sending the dummy dataset and by analyzing their behaviors in the networks.