http://msdn.microsof...28v=VS.85%29.aspx
The CryptUnprotectData function decrypts and does an integrity check of the data in a DATA_BLOB structure. Usually, the only user who can decrypt the data is a user with the same logon credentials as the user who encrypted the data. In addition, the encryption and decryption must be done on the same computer. For information about exceptions, see the Remarks section of CryptProtectData.