These are critical infrastructure employees who have access to the critical cyber assets in the first place. This situation is well recognized by international and national standardization bodies which recommend security education, training and awareness as one of the key elements of critical infrastructure protection. In this chapter the standards are identified and their relevant areas are described. A practical implementation...

These are critical infrastructure employees who have access to the critical cyber assets in the first place. This situation is well recognised by international and national standardisation bodies which recommend security education, training and awareness as one of the key elements of critical infrastructure protection. In this chapter the standards are identified and their relevant areas are described. A practical implementation...

An improved and extended version of a quaternion-based lossless encryption technique for digital image and communication on medicine (DICOM) images is proposed. We highlight and address several security flaws present in the previous version of the algorithm originally proposed by Dzwonkowski et al. (2015). The newly proposed secure quater- nion Feistel cipher (S-QFC) algorithm...

In this paper a quaternion-based modified Feistel Cipher is proposed. The algorithm is based on the scheme proposed by Sastry and Kumar (2012). Our algorithm uses special properties of quaternions to perform rotations of data sequences in 3D space for each of the cipher rounds. The plaintext (image in gray-tone) is divided into two square matrices of equal size which consist of Lipschitz quaternions. A modular arithmetic was implemented...