With sensitive data being increasingly stored on mobile devices and laptops, hard disk encryption is more important than ever. In particular, being able to plausibly deny that a hard disk contains certain information is a very useful and interesting research goal. However, it has been known for some time that existing \"Hidden volume\" solutions, like TrueCrypt, fail in the face of an adversary who is able to observe the contents of a disk on multiple, separate occasions. In this paper, the authors explore more robust constructions for hidden volumes and present HIVE, which is resistant to more powerful adversaries with multiple-snapshot capabilities. In pursuit of this, they propose the first security definitions for hidden volumes, and prove HIVE secure under these definitions.