Exchanging Cryptographic Keys

This section discusses situations when you must export keys from the secure environment of the CSP into a key BLOB.

There are two occasions when it is necessary to export keys:

• To save a session key for use by an application

  For example, if your application encodes a database file, and you want your application to decode this file later, the application must store the encryption key. This is necessary because CSPs do not preserve symmetric keys between sessions.

• To send a key to someone else

  This would be much easier for your application if the respective CSPs could communicate directly, but they cannot. This means that the key must be exported from your CSP, transmitted by your application to the destination application, and then imported to the destination CSP.

The following table shows functions you can use to create, configure, and destroy cryptographic keys, and to exchange them with other users.