| 摘要 |
PURPOSE:To reduce number of times of communication while keeping safety and high reliability without loss of the safety and high reliability even in the case of parallel processing by devising the method such that a certificated party indicates that the certificated party knows any ciphered plain sentence among ciphered sentences sent from a verification party through the interaction with the verification party in a way that the verification party is unaware of which of the ciphered sentences is known by the certificated party. CONSTITUTION:A certificated side equipment 9 consists of a random number generator 1, a memory 2, a computing element 3 and a decoder 4, and a verification party equipment 10 consists of a random number generator 6, a memory 7, and a computing element 8, and both the equipments make data communication through a communication line 5. Through the constitution above, the certificated party sends ciphered sentences resulting from ciphering at least two plain sentences at random to the verification party and suggests that the certificated party knows any one plain sentence among the ciphered sentences through the interaction with the verification party in a way that the verification party is unaware of which of the said ciphered sentences is known by the certificated party. The certificated party gets verification by indicating through the interaction with the verification party it that the certificated party knows any plain sentence among ciphered sentences sent from the verification party in a way that the verification party does not recognize which of the sentences the certificated party knows. Thus, number of times of communication is reduced without loss of the safety and high reliability even in the case of parallel processing. |
