An ownCloud Encryption app was released last week for ownCloud 5 , incorporating a much more secure AES algorithm rather than blowfish algorithm. This is built upon Open SLL. The app is integrated seamlessly within the ownCloud user interface as everything works in the background all other ownCloud features can still be used such as sharing , viewer apps , WebDAV access etc.. Therefore the encryption is taken place serverside rather than at hardware level, clientside encryption can still be added later if you wish. For those whom use the external storage app will benefit from serverside encryption.
One key item to note if that if a uses loses their log-in password they also lose access to all their data , but an admin can generate a recovery key which allows the recovery of data but this is an extra feature which needs to be implemented. So every user is able to decide if they want the protection against lost passwords. The Tizen OS on the Ultrabook supports the addition of the ownCloud service in it's list of accounts.
To find out more about how the encryption works or to test out the app visit Schiessle Blog