A device may receive, from a client device, a request with a single packet authorization (SPA) packet that includes data identifying a universal client device identifier (UID), a counter, a first one-time password generated based on a first shared key, the UID, and the counter. The device may generate a second shared key associated with the UID, and may compare the SPA packet to a comparison message authentication code (MAC) generated based on the second shared key, the UID, and the counter. The device may determine whether the SPA packet matches the comparison MAC, and may validate the client device when the SPA packet matches the comparison MAC. The device may provide a MAC associated with the SPA packet to the client device to enable the client device to validate the device for a secure communication based on establishing a pre-master key with the client device.