Patent ID: 7134070

Claim:
A method comprising: partitioning data into segments of the data; storing in memory a set of checksums of the segments of the data, the set of checksums having a first subset corresponding to the segments of data and a second subset corresponding to the segments of data shifted by a predetermined amount; selecting a portion of the data comprising at least one of a subset of the segments of the data and at least one part of at least one segment of the data; and determining a checksum of the portion of the data based upon at least one of a checksum of the subset of the segments of the data and a checksum of the at least one part of the at least one segment of the data, the checksum of the subset of the segments of the data being based, at least in part, upon respective checksums, read from the set of checksums stored in the memory, of segments of the data comprised in the subset of the segments of the data.