Parallelization of AES algorithm for disk encryption using CBC and ICBC modes

Abstract

Computers have become more prevalent and their interconnection via networks has increased the dependence of both organizations and individuals on the information stored and for communication using these systems. The end-user needs a faster, more capable system to keep up with this trend. At the same time security of data stored electronically is equally important. Disk encryption is a special case of data at rest protection when the storage media is a sector-addressable device. Advanced Encryption Standard (AES) is a symmetric key block cipher that gives maximum security because of longer key length, complex mathematical calculations, permutations and substitutions. Because of its complexity the execution time for the process of encryption is large. However with the advent of parallel computing and multicore processors there is a scope for parallelization of AES algorithm both at data and control level This paper proposes an optimized parallel architecture of AES algorithm for disk encryption, suitable to be implemented in a multicore environment. Cipher Block Chaining (CBC) mode of encryption is used for implementing the disk encryption. As it does not support a parallel architecture, Interleaved Cipher Block Chaining (ICBC) mode (proposed by the cryptographic community that allows parallel implementation) has been implemented. The AES algorithm in CBC and ICBC modes has been implemented in C language and is parallelized using OpenMP API 3.1 standard. The performance analysis is done using Intel VTune™ Amplifier XE 2013. The parallel design (ICBC) exhibits improved performance over the sequential approach (CBC) and a speed up of approximately 1.7 is achieved.