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Steganography Based on Genetic Algorithms and Differential Evolution
Published in Frank Y. Shih, Digital Watermarking and Steganography: Fundamentals and Techniques, 2017
Steganography aims at hiding information into covert channels, so that one can conceal the information and prevent the detection of hidden messages. For steganographic systems, the fundamental requirement is that the stego-object (the object containing hidden messages) should be perceptually indistinguishable to the degree that it does not raise suspicion. In other words, the hidden information introduces only slight modifications to the cover object (the original object containing no hidden messages). For image steganography, most passive wardens distinguish the stego-images by analyzing their statistical features. Since steganalytic systems analyze certain statistical features of an image, the idea of developing a robust steganographic system is to generate the stego-image while avoiding changes to the statistical features of the cover image.
C
Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
coupling factor a small capacitance to reduce the power line voltage to measureable levels. coupling factor in a coupler, the ratio of power in the coupled port to that applied at the input port. coupling efficiency the efficiency to which a signal can be coupled from one transmission line or resonator to another. coupling field a region of interaction where energy is transferred between systems. The energy may be transferred between systems of a similar nature (i.e., electrical-electrical) or between systems of a different nature (i.e., electrical- mechanical). coupling loss measure of the power dissipated as a result of coupling a signal from one transmission line or resonator to another. covariance the expectation of the product of two mean-removed random quantities: C f g (t1 , t2 ) = E f (t1 )g(t2 )T -E[ f (t1 )]E[g(t2 )T ] See also autocovariance, correlation, variance. covert channel a mechanism by means of which information can be communicated indirectly despite design features that prevent direct communication. Many covert channels utilize side effects of operations, such as effects on timing or scheduling that can be seen from programs or processes that are not supposed to be direct destinations of any communications from a sender that in fact performs operations that emit signals by affecting timing or scheduling within the system. COVQ tion. See channel optimized vector quantizacapture ferrous debris and prevent it from passing through the digestive system. CPA acronym for compensated pulsed alternator. See compulsator. CPI See color preference index or cycles per instruction. CPM laser laser. CPU See colliding pulse modelocked
Differential Evolution- Based Algorithm for Breaking the Visual Steganalytic System
Published in Frank Y. Shih, Multimedia Security, 2017
Frank Y. Shih, Venkata Gopal Edupuganti
As digital information and data are transmitted over the Internet more often than ever before, new technology for protecting and securing sensitive messages needs to be discovered and developed. Digital steganography is the art and science of hiding information into covert channels, so as to conceal the information and prevent the detection of the hidden message. Information security research on covert channels is generally not a major player, but has been an extremely active topic in academia, industry, and government domains for the last 30 years.
Assessing smart light enabled cyber-physical attack paths on urban infrastructures and services
Published in Connection Science, 2022
Ioannis Stellios, Kostas Mokos, Panayiotis Kotzanikolaou
Covert channels can occur when sources of electromagnetic, acoustic, thermal and/or optical wavelength are used as transmitters to create communication channels (Zhou et al., 2018). Ronen and Shamir (2016) proved that the exfiltration of potentially sensitive data from air-gaped systems is possible by creating a covert channel through the fast flickering of the light bulb whereas Zhou et al. (2018) managed to create a covert channel of an air-gaped system by exploiting the infrared interface. In Guri and Bykhovsky (2019), researchers achieved similar results by exploiting security cameras with infrared modules whereas Guri et al. (2016) managed to exfiltrate data via invisible to human eye, low contrast and/or fast flickering images. Similarly in Costin (2016), researchers managed to abuse the functionality of normal/Infrared LEDs to create hard-to-identify, optical covert channels and/or even disturb the normal operation of nearby visual equipment via Denial-of-Service (DoS) and jamming attacks. Ronen et al. (2016) proved that is possible to take over a large number of smart lighting systems via a self-propagation infection process by infecting just one smart lamp from a distance whereas in Sikder et al. (2019) researchers investigated the possibility of triggering events in a smart home environment by manipulating smart lighting system's presence sensors.
Identification of Network Application Behaviors Hiding in HTTP Tunnels
Published in IETE Technical Review, 2021
Huiwen Bai, Guangjie Liu, Weiwei Liu, Jiangtao Zhai, Luhui Yang, Yuewei Dai
HTTP protocol is commonly used in present diverse networks applications from traditional web services to mobile Internet, which makes network cybersecurity and management equipment in boundaries usually have to permit http traffic. For this reason, HTTP protocol has become the most suitable network traffic covers to build covert tunnels for hiding the network contents and behaviors. HTTP tunnels can be employed as a manner to circumvent censorship from the enterprise or the states. It can also be utilized as the covert channel between the remote server and the victim to communicate malicious commands and exfiltrate sensitive data. Because the packet payload is usually encrypted in the tunnel for bypassed the inspection at network boundaries, it is very important for the administrator of the network to figure out what happens in the tunnel and whether the traffic is allowed. For this reason, a fine-grained identification of user behaviors hiding in HTTP tunnels is necessary for network management and cybersecurity system.