We define a model for applications that process large data sets in a way that enables additional optimizations of encryption operations. We designed a new strong pseudo-random tweakable permutation, WCFB, to take advantage of identified characteristics. WCFB is built with only 2m+1 block cipher invocation for m cipherblocks and approximately 5m XOR operations.
WCFB can benefit from commonly occurring plaintext, such as encryption of a 0^nm sector, and repeated operations on the same wide block.
We prove the birthday-bound security of the mode, expressed in terms of the security of the underlying block cipher.
A case analysys of disk block access requests by Windows 8.1 is provided.
↧