The remote user may have used a browser that uses 128-bit keys to access the virtual gateway that supports only browsers with 256-bit keys by default. To resolve the problem, the user can either use a browser that uses 256-bit keys or use a 1024-bit key certificate as the local certificate on the virtual gateway. Between the two methods, the former is easier and is therefore recommended.
You can check the browser key length as follows (Internet Explorer 8 as an example):
- Open the Internet Explorer, click the help icon, and select About Internet Explorer.

- Check the Cipher Strength field for the key length used by the browser.
