Patent ID: 7616766

Claim:
A data division method for dividing original data into as many divided data as a desired number of divisions by using a prescribed processing unit bit length, comprising the steps of: generating a plurality of original partial data by dividing the original data by the prescribed processing unit bit length; generating a plurality of random number partial data each having a length equal to the prescribed processing unit bit length, from a random number having a length less than or equal to a bit length of the original data, in correspondence to the plurality of original partial data; generating a plurality of divided partial data that constitute each divided data by using exclusive OR calculation of the original partial data and the random number partial data, each divided partial data having a length equal to the prescribed processing unit bit length; and generating the divided data in the desired number of divisions from the plurality of divided partial data, such that the original data cannot be ascertained from any one divided data alone but the original data can be recovered from a prescribed number of the divided data among generated divided data.