Find the method to diversify application key

[Heather]

Is there any method to diversify the Application key? And I know that if I want to do diversify the key, diversification data is needed. How to achieve this data in Java Card Application? Thanks for any help.

[mabel]

To get diversification data, just select a security domain, and send "get data" with tag 42.
But pls note that not all cards support this get data. The alternative is to open an explicit secure channel. The diversification data are the 10 first bytes returned by init update. But you HAVE TO send a ext authenticate thereafter, because cards can be locked if you send too much init update without a successful authentication.