Abstract: There is provided an IPsec setting server apparatus capable of preventing inconsistency of setting among communicating apparatuses. An IPsec processing section subjects a data communication packet received from an interface section to IPsec processing. An SPD is referred to from the IPsec processing section and records policies for applying the IPsec. An SAD is referred to from the IPsec processing section and records an SA necessary for subjecting an individual kind of communication to the IPsec processing. A request processing section receives a setting request message from the IPsec processing apparatus and returns a distribution message. IPsec policies necessary for determining a requested setting are stored in a distribution policy storage section. Information on respective kinds of SA communication requested to be set is stored in a management table.