One embodiment of the present invention provides a system that enables a
background process to access encrypted data. During operation, the system
executes the background process. Next, the system obtains a set of
unencrypted keys by decrypting a set of encrypted keys with a server-key.
The system then makes the set of unencrypted keys available to the
background process, thereby enabling the background process to encrypt
and decrypt data. Finally, the system deletes the set of unencrypted
keys.