Electronic key registration method and electronic key registration system

Abstract

A method for registering first and second electronic keys, which are capable of controlling a communication subject, to a controller of the communication subject, wherein the first electronic key is to be initially registered, and the second electronic key is to be additionally registered, the method including: performing an additional key production process including storing, in the second electronic key, an additional encryption key generation code unique to the second electronic key and an additional encryption key that is used to verify the second electronic key; and performing a key additional registration process including obtaining the additional encryption key generation code from the second electronic key when identification information unique to the communication subject is stored in the second electronic key, generating the additional encryption key with an additional encryption key generation logic, and storing the additional encryption key in the controller.