Abstract: A method for encrypting a virtual disk comprises generating a hash value for each page of a first version of the virtual disk. Each page is encrypted using a unique initialization vector (IV). Each unique IV and each generated hash value is then stored in a plaintext hash database that maps each unique IV for a page to a corresponding hash value. For a second, updated version of the virtual disk, a hash value is generated for each page of the second version. It is then determined whether each newly generated hash value is stored in the plaintext hash database. If a first generated hash value for a first page of the second version of the virtual disk is stored in the plaintext hash database, such first page is encrypted using a unique IV from the plaintext hash database that corresponds to the first generated hash value.