METHOD AND DEVICE FOR PROVIDING IDENTITY OF PLAIN SENTENCE FOR PLURAL CIPHERED SENTENCES

摘要

PROBLEM TO BE SOLVED: To safely and efficiently prove the identity of plain sentence for plural ciphered sentences without disclosing secret information at all between a witness and a confirmer by preparing an information sequence which proves the identity of the plain sentence against the plural ciphered sentences by the witness and only confirming the identity without knowing the plain sentence by the confirmer. ;SOLUTION: A witness prepares a plain sentence having a special form and ciphered sentences against the plain sentence from open information for ciphering. Further, the witness prepares an information sequence which indicates the identity of the plain sentence, without informing the plain sentence to a confirmer, opens the information to the confirmer and the confirmer confirms the identity of the plain sentence utilizing the information sequence and the open information corresponding to the ciphered sentences. Thus, anyone proves the identity of the plain sentence of the plural ciphered sentences without disclosing at all the secret information of the witness (the person who prepares the ciphered sentences) and the plain sentence.;COPYRIGHT: (C)1999,JPO