Secure identification of intranet network

A method is provided for network identification based on high entropy data on a network which are not easily guessed or obtained outside the network, which can prevent an attacker from "spoofing" the network. A component in a client computer connected to a network may obtain over the network a network data block including device identification information of a device controlling the network. Upon parsing the network data block, such high entropy data as unique device identifiers may be obtained from the device identification information. Depending on availability of the unique device identifiers and authentication history of the client computer, different combinations of the unique device identifiers and/or other identification information may be used to generate a unique network identifier such as a network signature. The component may provide the network signature to applications within the client computer.