DISTRIBUTED DATA MANAGEMENT SYSTEM

摘要

PROBLEM TO BE SOLVED: To solve the following problems: in a conventional secret distribution scheme management method, original data can be easily restored if a common key is decrypted since one of a plurality of distributed data generated from the original data is encrypted by a common key and the common key is encrypted by a public key to be stored in one place together with the rest of distributed data; and in a threshold secret distribution scheme, the secrecy of information is insufficient since secret information can be partly restored if the prescribed number of pieces of distributed information are collected and, even if the number is short of the prescribed number, a specific part of the secret information can be restored by combining specific pieces of distributed information. SOLUTION: Elements of combination of five of divided information 21 are generated from secret information 20 by using a prime number pi, an integer xi, and a random number aijgenerated by respective means, and a distribution arrangement means 16 distributes (n) pieces of divided information 21 to each server 3 and manages them. As for restoration, a restoring means 19 can restore the divided information into the secret information 20 only when a restoration possibility discriminating means 18 discriminates that the collected divided information 21 satisfies conditions required for restoration. COPYRIGHT: (C)2009,JPO&INPIT