Controlling access to protected objects

A device operated by a user may store an object to which access is to be regulated, which may be achieved by encrypting the object with an encryption key and sending the key to a server having a key store. When a user of the device requests access to the object, the server may authenticate the user (e.g., according to a credential submitted by the user) and verify a trust identifier of the device (e.g., authorization to access the object through the device, and/or the integrity of the device), before sending to the device a ticket granting access to the key. The device may send the ticket to the server, receive the key from the server, decrypt the stored encrypted object, and provide the object to the user. This mechanism promotes rapid access upon request and efficient use of the server, and enables remote revocation of access.