Patent ID: 6928167

Claim:
A system for managing a public key in an environment having a hierarchical network with a domain name at each hierarchy, a DNS server provided at each hierarchy for managing correspondence between the domain name and an address, and hosts accommodated in the network, the DNS server serving to distribute a public key of another host to the host belonging to the network, the DNS server having means for managing the public key and a database for storing the public key of the host belonging to the network and the domain name in a corresponding manner, the method comprising: when a first host issues an inquiry about a public key of a second host on the information about the domain name, prompting the means for managing the public key to refer to the database, thereby answering the information on the public key of the second host corresponding to the domain name to the first host, wherein when the DNS server receives an inquiry of the public key of the second host from the first host, if no entry corresponding to the domain name of inquiry is found in the database of the DNS server itself, solution of the inquiry of the public key is recursively entrusted to another DNS server provided with the another means for managing a public key and the database along the hierarchy of the domain name.