KEY EXCHANGE DEVICE, KEY EXCHANGE METHOD, AND PROGRAM

摘要

PROBLEM TO BE SOLVED: To improve confidentiality of information on privacy in key exchange.SOLUTION: A key exchange device comprises: a contact address set information storage unit for storing contact address set information obtained by associating first contact address information which is contact address information for identifying a destination of information transmission and shows contact address information owned by the key exchange device with first conversion information showing conversion information obtained by converting the first contact address information on the basis of a predetermined unidirectional function; a key information storage unit for storing possessed key information for associating first contact address information whose key is previously acquired by the key exchange device with the key; and a control unit which acquires a set of second conversion information showing conversion information obtained by converting predetermined contact address information on the basis of the predetermined unidirectional function from a key exchange destination device, and determines a transmission key showing a key transmitted between the key exchange device and the exchange destination device on the basis of the acquired set of second conversion information, a set of the contact address set information stored by the contact address set information storage unit, and a set of the possessed key information stored by the key information storage unit.