SYSTEM FOR DISABLING UNAUTHORIZED PERSON, ENCRYPTION DEVICE, ENCRYPTION METHOD, AND PROGRAM

摘要

System for disabling an unauthorized person includes an encryption device (400) and a decryption device (500). The encryption device (400) contains distribution member set data as information on a member permitted to decrypt an encrypted text, a random number, and a public key. When the public key is inputted, the encryption device (400) generates and distributes: an error-attached encrypted text as an encrypted text containing the common key, the distribution member set data, and error information different for each of members; and an error correction encrypted text as an encrypted text of the error information. The decryption device (500) is connected to the encryption device (400) and contains a public key and a secret key corresponding to the decryption device (500). Upon reception of the error-attached encrypted text and the error correction encrypted text from the encryption device, the decryption device (500) checks whether the distribution member set data includes the decryption device (500). If yes, the decryption device (500) decrypts the error-attached encrypted text and the error correction encrypted text by using the public key and the secret key, removes error information from the decrypted error-attached encrypted text, and outputs the common key.