Method and apparatus for the secure distributed storage and retrieval of information

A secure distributed storage and retrieval system comprising:

• a plurality of servers connected in a communication network having a protocol which enables information files to be stored distributively throughout the network of servers and information files to be retrieved by any single server in the network using a retrieval protocol, one of said servers being designated as a gateway server for a user of the storage and retrieval system for a given transaction;
• and
• a computer depositing an encrypted file from the user and a file encrypting key encrypted under a public key of the user to the storage system via the gateway server, the gateway server distributing the file among a plurality of storage elements attached to servers within said storage system, the gateway server receiving a partial signature from each of the servers receiving parts of the distributed file, the gateway server generating an authenticated proof that the storage system received and correctly stored the file, the proof being provided even when at least one of said servers malfunctions due to a malicious fault, the gateway server responding to a user request for a previously stored file by forwarding the request to all servers in the storage system, the user request including an encryption under the user's public key of a user generated random number temporarily stored by the user, the random number serving as a blinding factor, each server checking to determine if the user making the request has permission to access the requested file, each server computing a partial decryption of their respective share of the requested file encrypting key multiplied by the encrypted blinding factor using a threshold decryption algorithm if the user making the request has permission to access the requested file, each server sending the computed partial decryption their respective shares of the stored file and hashes of all shares to the gateway server, the gateway server determining good shares from a majority of hashes received from other servers and reconstituting the encrypted file using an information dispersal algorithm, the gateway server determining the file-encrypting key multiplied by the blinding factor, sending the reconstituted file and the product of the encrypting key multiplied by the blinding factor to said computer, obtaining the file-encrypting key by the user by dividing out the blinding factor, receiving from said computer an authenticated acknowledgment message, and forwarding an acknowledgment message to all servers in the storage system, and the servers echoing the acknowledgment message.