DYNAMIC SUBSTITUTION BOXES OF SYMMETRIC BLOCK ENCRYPTION ALGORITHMS

The paper deals with nonlinear transformations of well-known symmetric block algorithms such as AES, Kuznyechik, SM4, BelT, and Kalyna. A brief description of the substitution boxes for these algorithms is given. The properties of nonlinearity of the described substitution boxes are investigated with the calculation of the corresponding values. Based on the property of nonlinearity, a method for generating a dynamic substitution box is proposed. The purpose of this method is to generate dynamic substitution boxes (S-boxes) that change depending on the values of some parameter obtained from the secret key of the algorithm. Considering that linear and differential cryptanalysis uses known substitution boxes, the main advantage of the new method is that S-boxes are randomly key-dependent and unknown. Experiments were also carried out to implement this method. The resulting dynamic substitution boxes were tested for nonlinearity and the results were compared with the original nonlinearity values of the same substitution boxes.

Block algorithms to solve Zheng/Chen/Zhang's finite-difference equations

This paper is devoted to the design of multiblock algorithms of the FDTD-method intended for computations based on a Zheng-Chen-Zhang implicit finite-difference scheme. Special emphasis is placed on experimental research of the designed algorithms and detecting specific features of the multiblock computing based on implicit finite-difference equations. The efficiency of the proposed approaches is proved by a six-fold speed-up of computations.

Design features of block algorithms of FDTD-method implemented on a GPU using MATLAB

The paper is devoted to the investigation of the implementation features of a block algorithm for the FDTD-method on GPU. The block algorithm in general and in the context of the FDTD-method in particular is discussed. The main attention is paid to specifics of determining the shape and volume of blocks, which stem from the use of MATLAB and its Parallel Computing Toolbox. The practical efficiency of the proposed techniques is shown. Possible applications and prospects are discussed.

RANCANGAN APLIKASI PENGAMANAN DATA DENGAN ALGORITMA ADVANCED ENCYPTION STANDARD (AES)

ABSTRAKData sangatlah berharga bagi semua pengguna komputer, belakangan ini kriptografi menjadi metode yang digunakan dalam mengamankan data. Kriptografi adalah ilmu yang mempelajari teknik-teknik matematika dalam mengamankan suatu informasi atau pesan asli (Plainteks) menjadi sebuah teks tersembunyi (Chiperteks) dan kemudian di ubah menjadi pesan asli kembali. Kriptografi mempunyai tiga unsur penting yaitu pembangkitan kunci, enkripsi dan deskipsi. Dalam kriptografi di kenal algoritma block chiper yang didalamnya terdapat AES (Anvanced Encyption Standard) merupakan bagian dari Modern Symmetric Key Cipher, algoritma ini menggunakan kunci yang sama pada saat proses enkripsi dan deskripsi sehingga data yang kita miliki akan sulit dimengerti maknanya. Teknik algoritma tersebut digunakan untuk mengkonversi data dalam bentuk kode-kode tertentu, untuk tujuan agar informasi yang tersimpan tidak bisa di baca siapa pun kecuali orang-orang yang berhak. Oleh karena itu, sistem keamanan data sangat di perlukan untuk menjaga kerahasian informasi agar tetap terjaga. ABSTRACTData is a valueable for all computer users, cryptography is the one of method used to securing data. Cryptography is the study of mathematical techniques in securing an information or original message (Plainteks) into a hidden text (Chiperteks) and then converted into the original message again. Cryptography has three important elements, first is key generation, second is encryption and latetly is description. In cryptography known as cipher block algorithms in which AES (Advanced Encyption Standard) is part of Modern Symmetric Key Cipher, this algorithm uses the same key during the encryption and description process so that the data we have will be difficult to understand. The algorithm technique is used to convert data in the form of certain codes, so that the information stored cannot be read by anyone except those who are entitled. Therefore, the data security system is very necessary to maintain the confidentiality of information.