3 research outputs found
Cryptanalysis of an Image Cipher using Multi entropy Measures and the Countermeasures
The use of same keys or equivalent keys should not be occurred in cryptographic communications because a cipher system utilising such keys to secure messages can be attacked even it possesses excellent cryptographic characteristics for extracting intelligible information from encrypted messages. Identification of crypts formed with such keys is an important task of traffic analysis of cryptographic communications to check the applicability of two-messages-on-same-key (TMSK) attack. To avoid its applicability, adequate safeguards are required. In the paper, we cryptanalyze stream encryption based cipher system and propose an intelligent identification methodology using multi-entropy measures and soft decision criteria for identification of encrypted images of same or equivalent keys. Experimental test results show that the crypts formed with same keys can be identified successfully with high precision. We also present the countermeasures against TMSK attack
A reversible system based on hybrid toggle radius-4 cellular automata and its application as a block cipher
The dynamical system described herein uses a hybrid cellular automata (CA)
mechanism to attain reversibility, and this approach is adapted to create a
novel block cipher algorithm called HCA. CA are widely used for modeling
complex systems and employ an inherently parallel model. Therefore,
applications derived from CA have a tendency to fit very well in the current
computational paradigm where scalability and multi-threading potential are
quite desirable characteristics. HCA model has recently received a patent by
the Brazilian agency INPI. Several evaluations and analyses performed on the
model are presented here, such as theoretical discussions related to its
reversibility and an analysis based on graph theory, which reduces HCA security
to the well-known Hamiltonian cycle problem that belongs to the NP-complete
class. Finally, the cryptographic robustness of HCA is empirically evaluated
through several tests, including avalanche property compliance and the NIST
randomness suite.Comment: 34 pages, 12 figure
Cryptography and Its Applications in Information Security
Nowadays, mankind is living in a cyber world. Modern technologies involve fast communication links between potentially billions of devices through complex networks (satellite, mobile phone, Internet, Internet of Things (IoT), etc.). The main concern posed by these entangled complex networks is their protection against passive and active attacks that could compromise public security (sabotage, espionage, cyber-terrorism) and privacy. This Special Issue “Cryptography and Its Applications in Information Security” addresses the range of problems related to the security of information in networks and multimedia communications and to bring together researchers, practitioners, and industrials interested by such questions. It consists of eight peer-reviewed papers, however easily understandable, that cover a range of subjects and applications related security of information