In cryptography, a Substitution box (S-box) is one of the basic components of a symmetric key cryptography. Generally, it transforms a number of m input bits into n output bits. In this paper, there are presented the cryptographic properties of S-boxes and it is introduced a knowledge-based schema for building S-boxes.

In this paper, we present an Energy Efficient Secure Routing Protocol for Sensor Networks (ESecRout). The protocol uses the symmetric cryptography to secure messages, and uses a small cache in sensor nodes to record the partial routing path (previous and next nodes) to the destination. It guarantees that the destination will be able to identify and discard the tampered messages and ensure that ...

This paper presents a quasigroup encryptor that has very good data-scrambling properties and, therefore, it has potential uses in symmetric cryptography. The purpose of the scrambler is to maximize the entropy at the output, even in cases where the input is constant. The great complexity associated with the task of finding the scrambling transformation ensures the effectiveness of the encryptio...

Remotely keyed encryption (RKE) schemes provide fast symmetric encryption and decryption using a small-bandwidth security module and a powerful host. Such schemes keep the key inside the security module to prevent key compromise. Shin, Shin, and Rhee proposed a length-preserving as well as a length-increasing RKE scheme that both use only a single round of interaction between host and security ...

The need for secure communication between the nodes in a network has led to the development of various key distribution schemes. Blom’s scheme is a prominent key exchange protocol used for sensor and wireless networks, but its shortcomings include large computation overhead and memory cost. In this paper, we propose an efficient key management scheme by generating new public and private keys. W...

Wireless sensor networks (WSNs) are ad hoc networks comprised mainly of small sensor nodes with limited resources, and can be used to monitor areas of interest. In this paper, we propose a solution for securing heterogeneous hierarchical WSNs with an arbitrary number of levels. Our solution relies exclusively on symmetric key schemes, is highly distributed, and takes into account node interacti...

This work describes an example of an application of a novel method for symmetric cryptography. Its purpose is to show how a regular message can be encrypted and then decrypted in an easy, yet secure way. The encrypting method introduced in this work is different from others because it involves decimals as well as integers, encrypting the same initial message differently every time, and insertin...