keygen html tag on iOS6, how to make it work ?

The Safari reference manual indicates that the <keygen> tag has been available since iOS 1.0.

https://developer.apple.com/library/safari/documentation/AppleApplications/Refer ence/SafariHTMLRef/Articles/HTMLTags.html#//apple_ref/doc/uid/30001262-keygen

Is there some trick to make it work ?

All I get is an empty dropdown, when browsing with Safari on an iPad (iOS 6.1.3). Posting the form does not perform key generation.

Using the iOS Simulator 6 also provides the same results: empty dropdown, no keygen.

This test site hosted by the Mozilla.org provides a basic keygen test. The page renders correctly with Safari on OSX (also Mozilla, and Chrome on OSX).

https://bug474958.bugzilla.mozilla.org/attachment.cgi?id=380749

Do I need to install additional software on my iPad ?