Technology for providing secure communications between a user device and a secure server, in which a user device performs a certificate pinning operation by requesting and receiving a set of public key certificates for the secure server from a dynamic host configuration protocol (DHCP) server. The user device requests and receives a current public key certificate of the secure server from the secure server. The current public key certificate of the secure server is compared with the set of public key certificates for the secure server received from the DHCP server. In response to the current public key certificate of the secure server matching one of the public key certificates in the set of public key certificates for the secure server received from the DHCP server, the authenticity of the secure server is confirmed and communications are permitted between the user device and the secure server.