It is an object of the present invention to solve a problem included in the onion routing which is used as a confidential communication method, that if a system down occurs in a computer within a communication route, connection is not made to further components at all, or a problem that the system and the traffic become slow by using multiplexed encryption. It is a communication method in which a client of an information providing source encrypts random numbers and calculates its hash value using respective public keys of an information server to which it connects, a function server of a destination to be sent, and an information server to which the function server connects, respective servers decrypt the encrypted random number using their own secret keys to compare the random number with the hash value, and thus, the client determines whether or not the route is related to the client. In such a way, information can be provided as an information providing source and an information provided destination are hidden, and as a response to provided contents from the function server which is the information provided source can also be kept anonymous.