As society increasingly relies on digitally stored and accessed information, supporting the availability, integrity and confidentiality of this information is crucial. We need systems in which users can securely store critical information, ensuring that it persists, is continuously accessible, cannot be destroyed and is kept confidential. A survivable storage system would provide these guarantees over time and despite malicious compromises of storage node subsets. The PASIS architecture flexibly and efficiently combines proven technologies (decentralized storage system technologies, data redundancy and encoding, and dynamic self-maintenance) for constructing information storage systems whose availability, confidentiality and integrity policies can survive component failures and malicious attacks.