A General Construction of Tweakable Block Ciphers and Different Modes of Operations

Abstract

This work builds on earlier work by Rogaway at Asiacrypt 2004 on tweakable block cipher (TBC) and modes of operations. Our first contribution is to generalize Rogaway's TBC construction by working over a ring R and by the use of a masking sequence of functions. The ring R can be instantiated as either GF(2n) or as ℤ2n . Further, over GF(2n), efficient instantiations of the masking sequence of functions can be done using either a Linear Feedback Shift Register (LFSR), a powering construction or a cellular automata map. Rogaway's TBC construction was built from the powering construction over GF(2n). Our second contribution is to use the general TBC construction to instantiate general constructions of various modes of operations (AE, PRF, MAC, AEAD) given by Rogaway.