DATA DIVISION/RESTORATION SYSTEM, TERMINAL, DATA DIVISION/RESTORATION METHOD AND COMPUTER PROGRAM

PROBLEM TO BE SOLVED: To allow efficient processing of division, restoration when at least one storage device which stores divided data is accessed via a network. SOLUTION: In division processing of original data, the original data S are divided into three by a divided data generation part 11, divided data A are stored in a storage part 14 built in a terminal 1, divided data B are stored in an external storage device 2 and divided data C (random numbers) are stored in a storage part 31 of a data center 3 via the network 4. In restoration processing of the original data, when both of the storage part 14 and the external storage device 2 are usable, processing for acquiring the divided data C from the storage part 31 of the data center 3 via the network 4 is made unnecessary by reading the divided data A and the divided data B from each of the storage part 14 and the external storage device 2 by an original data restoration part 12 and calculating the random numbers (divided data C) by exclusive OR between both. Then, the original data are restored by using the calculated random numbers and pieces of the read divided data A, B. COPYRIGHT: (C)2007,JPO&INPIT