In one aspect, the present invention comprises one or more processors that generate a first checksum value for a data block and a second checksum value for the data block, wherein the first checksum value is generated by applying a first checksum algorithm to the data block and the second checksum value is generated by applying a second checksum algorithm, different from the first checksum algorithm, to the data block; one or more processors operable to create a data entry comprising data identifying: the first and second checksum values, the first and second checksum algorithms, and at least one of the identified attributes of the data block, the data entry not comprising the data block, and wherein the data block can be recovered using the data entry; and one or more processors that store the data entry in a computer-readable medium. Other aspects comprise related systems, methods, and software.