Passive Defense In Infrastructure Networks Based on Cryptanalysis Stream Cipher Algorithms

Communication networks as one of the country's critical infrastructures are considered as testbeds for various communication applications and its use is increasing rapidly. Due to lack of security in communication networks along with the undeniable benefits, serious and irreparable challenges would be created in the country. Comprehensive understanding of network security problems and measures to overcome the major problems in this area, a significant role in the convention to promote security, safety and sustainability of infrastructure and communications will play a major step toward securing the objectives of passive defense in this regard. One of the most important types of stream ciphers are symmetric encryption algorithms that are appropriate to the specific features and in some applications such as network security and telecommunications infrastructure, the security assessment is an important consideration in the areas of passive defense and international project eSTREAM in line with increased activity in this branch of cryptography can play an important role. This article, cryptanalyzes one of the stream ciphers based on array rolling with distinguishing attack. The main idea of introducing a distinguisher on HC-256'. In this attack we need about 2556 linear equations involving binary keystream variables.