Abstract: Preservation of sensitive electronic data records in the face of either natural or man-made catastrophes has become important. In some fields, such as the medical and legal fields, current law requires that such data survive these events, and be available to authorized users in a timely fashion. This invention presents a method to protect sensitive data such that the systems used for preservation need be neither private nor secure. Data sets are replicated at multiple servers that can be geographically distant increasing the survivability of these records. Both the name and the contents of these files are private to the client, and are not available even to the operators of the disaster recovery system. By allowing the preserved data to be accessible on the public Internet, yet be undecipherable, the confidentiality and survival of such data is significantly improved. This preservation methodology minimizes the data to be sent by sending only new and changed files, and multiple geographic sites are supported.