Biblio

Adaptation of e-commerce in third world countries requires more secure computing facilities. Online data is vulnerable and susceptible to active attacks. Hundreds of security mechanisms and services have been proposed to curb this challenge. However, available security mechanisms, sufficiently strong, are heavy for the machines used. To secure online data where machines' processing power and memory are deficient, a Hybrid Encryption Standard (HES) is proposed. The HES is built on the Data Encryption Standard (DES) algorithm and its siblings. The component units of the DES are redesigned towards reduced demands for processing power and memory. Precisely, white box designs of IP tables, PC tables, Expansion tables, Rotation tables, S-boxes and P-boxes are proposed, all aimed at reducing the processing time and memory demands. Evaluation of the performance of the HES algorithm against the performance of the traditional DES algorithm reveal that the HES out-performs the DES with regards to speed, memory demands, and general acceptance by novice practitioners in the cryptography field. In addition, reproducibility and flexibility are attractive features of the HES over the DES.

The DES is a symmetric cryptosystem which encrypts data in blocks of 64 bits using 48 bit keys in 16 rounds. It comprises a key schedule, encryption and decryption components. The key schedule, in particular, uses three static component units, the PC-1, PC-2 and rotation tables. However, can these three static components of the key schedule be altered? The DES development team never explained most of these component units. Understanding the DES key schedule is, thus, hard. In addition, reproducing the DES model with unknown component units is challenging, making it hard to adapt and bring implementation of the DES model closer to novice developers' context. We propose an alternative approach for re-implementing the DES key schedule using, rather, dynamic instead of static tables. We investigate the design features of the DES key schedule and implement the same. We then propose a re-engineering view towards a more white-box design. Precisely, generation of the PC-1, rotation and PC-2 tables is revisited to random dynamic tables created at run time. In our views, randomly generated component units eliminate the feared concerns regarding perpetrators' possible knowledge of the internal structures of the static component units. Comparison of the performances of the hybrid DES key schedule to that of the original DES key schedule shows closely related outcomes, connoting the hybrid version as a good alternative to the original model. Memory usage and CPU time were measured. The hybrid insignificantly out-performs the original DES key schedule. This outcome may inspire further researches on possible alterations to other DES component units as well, bringing about completely white-box designs to the DES model.