System and method for electronically storing essential data

A method for storing electronic data blocks at a storage facility uses a public database and a select database. Hash for each data block is evaluated at the facility to determine whether the data block is already stored at the facility. New data blocks are assigned a new address in the select database when encrypted with a customer key. Otherwise, they are assigned a new address in the public database by default. Duplicate data blocks are assigned a previously established address for the data block in either the public or select database. All addresses are then sent to the customer location for file integrity and only the content of new data blocks need to be sent to the storage facility (i.e. no need for duplicates).