Often it can be beneficial to ‘more’ uniquely identify your users. For applications this is trivial, but in a web browser this can be accomplished via only a few attributes.
- HTTP – User-Agent, IP Address, Content types and languages accepted.
- HTTPS/SSL – the keys and encryption methods available to a specific user may vary for each client configuration.
- HTML5 – local storage and capabilities supported.
- Geolocation – this is included in HTML5, but also supported in many clients without full HTML5 support, or via browser extensions.
- JavaScript – Installed version – and many DOM attributes/capabilities such as timezone, installed plugins, screen sizes and fonts from the browser can be detected.
- Java (Applet) – Installed version – this can often be used to get additional information regarding the client system directly from the VM or Operating System itself. (* Persistent Cookies possible)
- Flash – Installed version – this can often be used to get additional information regarding the client system directly from the Operating System itself. (* Persistent Cookies possible)
- Silverlight (for Microsoft Windows) – – Installed version and additional information from Operating System?
- GoogleGEARS (deprecated) – Installed version and additional information from Operating System such as Geolocation
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