A method for securely assigning a DHCP protocol address, comprising: receiving, by an access server, a discovery message in the DHCP protocol (91); the insertion, by the access server, of location information of the DHCP client in the DHCP protocol discovery message (93); sending, by the access server, the DHCP protocol discovery message with the location information of the DHCP client to a DHCP protocol authentication server (93); the reception, by the DHCP protocol authentication server, of the DHCP protocol discovery message with the location information of the DHCP client (93); characterized in that: the DHCP protocol authentication server is a DHCP protocol server having a locally configured authentication function, the DHCP protocol authentication server comprising a local database comprising identification information stored for a valid subscriber at the level local; wherein the method further comprises: the realization, by the DHCP protocol authentication server, of a DHCP client authentication based on the location information and identification information memorized for the locally valid subscriber and the sending, by the DHCP protocol authentication server, of a DHCP protocol message with address information that is assigned to the DHCP client that has transmitted the authentication through the access server, after authentication of the authentication has been successful DHCP server client (96).