DIFFERENTIAL DATA CREATING SYSTEM, DATA UPDATING SYSTEM, AND DIFFERENTIAL DATA CREATING METHOD

摘要

The purpose of the present invention is to provide a technology capable of enhancing the effect of reducing the size of differential data. A bit shift unit 4a shifts either old data or new data by each of 0, 1, 2, ···, and n bits in the forward direction and the backward direction of a bit string thereof, thereby creating a plurality of data. A copy bit string extracting unit 4b extracts copy bit string information on the basis of the plurality of data and other data not shifted. An additional bit string extracting unit 4c extracts additional bit string information obtained by excluding the copy bit string from the new data. A differential data creating unit 6 creates differential data on the basis of the copy bit string information and the additional bit string information.