Improved intrusion detection and/or tracking methods and systems are provided for use across various computing devices and networks. Certain methods, for example, form a substantially unique audit identifier during each authentication/logon process. One method includes identifying one or more substantially unique parameters that are associated with the authentication/logon process and encrypting them to form at least one audit identifier that can then be generated and logged by each device involved in the authentication/logon process. The resulting audit log file can then be audited along with similar audit log files from other devices to track a user across multiple platforms.