How to encrypt data -- on card or off card

[Diorin]

Due to security reason, I should store encrypted data in java card. And there is two methods to aim this goal.

1. Encrypt data with offcard application and then send it to javacard.
2. Send data to java card and let java card encrypt it.

In consideration of SECURITY, Which one is best method to do this?

[horse dream]

Basically it depends what you call the off-card application, and whether you consider it trusted.
Anyway to answer your question, the private data managed by the card application does not need to be encrypted before being stored, because the storage can be considered safe.