scholarly journals A Wireless Covert Channel Based on Dirty Constellation with Phase Drift

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 647
Author(s):  
Krystian Grzesiak ◽  
Zbigniew Piotrowski ◽  
Jan M. Kelner
Keyword(s):  
Software Defined Radio ◽  
Modulation Method ◽  
Practical Implementation ◽  
Covert Channel ◽  
Audio Signals ◽  
Covert Channels ◽  
Simulation Research ◽  
Phase Drift ◽  
Modulation Type ◽  
Shift Keying

Modern telecommunications systems require the use of various transmission techniques, which are either open or hidden. The open transmission system uses various security techniques against its unauthorized reception, and cryptographic solutions ensure the highest security. In the case of hidden transmissions, steganographic techniques are used, which are based on the so-called covert channels. In this case, the transparency and stealth of the transmission ensure its security against being picked up by an unauthorized user. These covert channels can be implemented in multimedia content, network protocols, or physical layer transmissions. This paper focuses on wireless covert channels. We present a novel method of steganographic transmission which is based on phase drift in phase-shift keying or quadrature amplitude modulation (QAM) and is included in the so-called dirty constellation techniques. The proposed approach is based on the drift correction modulation method, which was previously used in the watermarking of audio-signals. The developed solution is characterized by a variable bit rate, which can be adapted to the used modulation type and transmission conditions occurring in radio channels. In the paper, we present the method of generating and receiving hidden information, simulation research, and practical implementation of the proposed solution using the software-defined radio platform for selected QAM.

scholarly journals Application of Ultra Narrow Band Modulation in Enhanced Loran System

Sensors ◽  
2021 ◽  
Vol 21 (13) ◽  
pp. 4347
Author(s):  
Boyun Lyu ◽  
Yu Hua ◽  
Jiangbin Yuan ◽  
Shifeng Li
Keyword(s):  
Narrow Band ◽  
Data Rate ◽  
Modulation Method ◽  
Phase Shift Keying ◽  
Spectrum Utilization ◽  
Frequency Domains ◽  
Shift Keying ◽  
Modulation Methods ◽  
Binary Phase Shift Keying ◽  
Signal Time

The Enhanced Loran (eLoran) system is valued for its important role in the positioning, navigation, and timing fields; however, with its current modulation methods, low data rate restricts its development. Ultra narrow band (UNB) modulation is a modulation method with extremely high spectrum utilization. If UNB modulation can be applied to the eLoran system, it will be very helpful. The extended binary phase shift keying modulation in UNB modulation is selected for a detailed study, parameters and application model are designed according to its unique characteristics of signal time and frequency domains, and it is verified through simulation that the application of this modulation not only meets the design constraints of the eLoran system but also does not affect the reception of the respective signals of both parties. Several feasible schemes are compared, analyzed, and selected. Studies have revealed that application of UNB modulation in the eLoran system is feasible, and it will increase the data rate of the system by dozens of times.

scholarly journals Addressing Covert Channel Attacks in RFID-Enabled Supply Chains

2013 ◽  
pp. 176-190
Author(s):  
Kirti Chawla ◽  
Gabriel Robins
Keyword(s):  
Supply Chain ◽  
Supply Chains ◽  
Network Flow ◽  
Economic Effects ◽  
Future Research ◽  
Covert Channel ◽  
Covert Channels ◽  
Node Selection ◽  
Future Research Directions ◽  
Key Nodes

RFID technology can help competitive organizations optimize their supply chains. However, it may also enable adversaries to exploit covert channels to surreptitiously spy on their competitors. We explain how tracking tags and compromising readers can create covert channels in supply chains and cause detrimental economic effects. To mitigate such attacks, the authors propose a framework that enables an organization to monitor its supply chain. The supply chain is modeled as a network flow graph, where tag flow is verified at selected key nodes, and covert channels are actively sought. While optimal taint checkpoint node selection is algorithmically intractable, the authors propose node selection and flow verification heuristics with various tradeoffs. The chapter discusses economically viable countermeasures against supply chain-based covert channels, and suggests future research directions.

scholarly journals A reconfigurable software defined ultra-wideband impulse radio transceiver

2010 ◽  
Vol 8 ◽  
pp. 67-73 ◽  
Author(s):  
M. D. Blech ◽  
A. T. Ott ◽  
P. Neumeier ◽  
M. Möller ◽  
T. F. Eibert
Keyword(s):  
Software Defined Radio ◽  
Matched Filter ◽  
Digital Signal ◽  
Impulse Radio ◽  
Ultra Wideband ◽  
Modulation Scheme ◽  
Digital To Analog Converter ◽  
Shift Keying ◽  
Reconfigurable Software ◽  
Radio Transceiver

Abstract. An ultra-wideband (UWB) software defined radio (SDR) implementation is presented. The developed impulse radio (IR) transceiver employs first order bandpass (BP) sampling at a conversion frequency which is four times the channel bandwidth. The subsampling architecture directly provides the RF signal avoiding any non-ideal mixer stages and reduces the requirements of digital signal processing implemented in a field programmable gate array (FPGA). The transmitter consists basically of a multi-Nyquist digital to analog converter (DAC), whereas the implemented matched filter (MF) receiver prototype employs a standard digitizing oscilloscope. This design can be adaptively reconfigured in terms of modulation, data rate, and channel equalization. The reconfigurable design is used for an extensive performance analysis of the quadrature phase shift keying (QPSK) modulation scheme investigating the influence of different antennas, amplifiers, narrowband interferers as well as different equalizer lengths. Even for distances up to 7 m in a multipath environment robust communication was achieved.

scholarly journals A New Sensors-Based Covert Channel on Android

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Ahmed Al-Haiqi ◽  
Mahamod Ismail ◽  
Rosdiadee Nordin
Keyword(s):  
Covert Channel ◽  
Security Model ◽  
Covert Channels ◽  
Computing Systems ◽  
Collusion Attacks ◽  
Acceleration Data ◽  
Universal Solution ◽  
Android Platform ◽  
New Sensors ◽  
Explicit Communication

Covert channels are not new in computing systems, and have been studied since their first definition four decades ago. New platforms invoke thorough investigations to assess their security. Now is the time for Android platform to analyze its security model, in particular the two key principles: process-isolation and the permissions system. Aside from all sorts of malware, one threat proved intractable by current protection solutions, that is, collusion attacks involving two applications communicating over covert channels. Still no universal solution can countermeasure this sort of attack unless the covert channels are known. This paper is an attempt to reveal a new covert channel, not only being specific to smartphones, but also exploiting an unusual resource as a vehicle to carry covert information: sensors data. Accelerometers generate signals that reflect user motions, and malware applications can apparently only read their data. However, if the vibration motor on the device is used properly, programmatically produced vibration patterns can encode stolen data and hence an application can cause discernible effects on acceleration data to be received and decoded by another application. Our evaluations confirmed a real threat where strings of tens of characters could be transmitted errorless if the throughput is reduced to around 2.5–5 bps. The proposed covert channel is very stealthy as no unusual permissions are required and there is no explicit communication between the colluding applications.

scholarly journals A Survey of Key Technologies for Constructing Network Covert Channel

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Jing Tian ◽  
Gang Xiong ◽  
Zhen Li ◽  
Gaopeng Gou
Keyword(s):  
Communication Technology ◽  
Network Architecture ◽  
The Internet ◽  
Covert Channel ◽  
Free Access ◽  
Transmission Network ◽  
Information Channel ◽  
Covert Channels ◽  
Key Technologies ◽  
Network Covert Channel

In order to protect user privacy or guarantee free access to the Internet, the network covert channel has become a hot research topic. It refers to an information channel in which the messages are covertly transmitted under the network environment. In recent years, many new construction schemes of network covert channels are proposed. But at the same time, network covert channel has also received the attention of censors, leading to many attacks. The network covert channel refers to an information channel in which the messages are covertly transmitted under the network environment. Many users exploit the network covert channel to protect privacy or guarantee free access to the Internet. Previous construction schemes of the network covert channel are based on information steganography, which can be divided into CTCs and CSCs. In recent years, there are some covert channels constructed by changing the transmission network architecture. On the other side, some research work promises that the characteristics of emerging network may better fit the construction of the network covert channel. In addition, the covert channel can also be constructed by changing the transmission network architecture. The proxy and anonymity communication technology implement this construction scheme. In this paper, we divide the key technologies for constructing network covert channels into two aspects: communication content level (based on information steganography) and transmission network level (based on proxy and anonymity communication technology). We give an comprehensively summary about covert channels at each level. We also introduce work for the three new types of network covert channels (covert channels based on streaming media, covert channels based on blockchain, and covert channels based on IPv6). In addition, we present the attacks against the network covert channel, including elimination, limitation, and detection. Finally, the challenge and future research trend in this field are discussed.

scholarly journals An Energy-Synchronous Direct Antenna Modulation Method for Phase Shift Keying

2020 ◽  
Vol 1 ◽  
pp. 41-46
Author(s):  
Kurt Schab ◽  
Danyang Huang ◽  
Jacob J. Adams
Keyword(s):  
Phase Shift ◽  
Modulation Method ◽  
Phase Shift Keying ◽  
Shift Keying

scholarly journals A Novel Chaotic System with a Line Equilibrium: Analysis and Its Applications to Secure Communication and Random Bit Generation

Telecom ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 283-296
Author(s):  
Lazaros Moysis ◽  
Christos Volos ◽  
Ioannis Stouboulos ◽  
Sotirios Goudos ◽  
Serdar Çiçek ◽  
...  
Keyword(s):  
Chaotic System ◽  
Secure Communication ◽  
Three Dimensional ◽  
Equilibrium Analysis ◽  
Modulation Method ◽  
Secure Communications ◽  
Information Signal ◽  
Shift Keying ◽  
Binary Information ◽  
Chaos Shift Keying

In this study, a novel two-parameter, three-dimensional chaotic system is constructed. The system has no linear terms and its equilibrium is a line, so it is a system with hidden attractors. The system is first studied by computation of its bifurcation diagrams and diagram of Lyapunov exponents. Then, the system is applied to two encryption related problems. First, the problem of secure communications is considered, using the symmetric chaos shift keying modulation method. Here, the states of the chaotic system are combined with a binary information signal in order to mask it, safely transmit it through a communication channel, and successfully reconstruct the information at the receiver end. In the second problem, the states of the system are utilized to design a simple rule to generate a bit sequence that possesses random properties, and is thus suitable for encryption related applications. For both applications, simulations are performed through Matlab to verify the soundness of the designs.

Overcoming of a Resonance Stall and the Minimization of Amplitudes in the Transient Resonance of a Vibratory Machine by the Phase Modulation Method

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
J. Michalczyk ◽  
Ł. Bednarski
Keyword(s):  
Angular Velocity ◽  
General Model ◽  
Phase Modulation ◽  
Modulation Method ◽  
Practical Implementation ◽  
Control Value ◽  
Unbalanced Rotor ◽  
Transient Resonance ◽  
Modulation Methods ◽  
The Impact

The present paper elucidates the difficulties faced in the practical implementation of phase modulation methods in the form that was presented by Wang et al. and in the actual systems where the motor driving moment is the control value. A more general model, which takes into consideration the impact of machine vibrations on the rotor angular velocity, was developed. The modification of the phase modulation method is also proposed. The usefulness of such an approach for shaping the transient resonance of the machines with an unbalanced rotor is proven by means of a simulation and an experiment.

Research on Construction Methods for Network Covert Channels Based on HTTP

2012 ◽  
Vol 220-223 ◽  
pp. 2528-2533
Author(s):  
Ran Zhang ◽  
Yong Gan ◽  
Yi Feng Yin
Keyword(s):  
Network Traffic ◽  
Covert Channel ◽  
Construction Technology ◽  
Traffic Data ◽  
Covert Channels ◽  
Secret Data ◽  
Construction Methods ◽  
Working Principle ◽  
Network Covert Channel

Network covert channel is a steganography technology that uses network traffic data as a carrier to transfer the secret data. This paper analyzes the working principle of network covert channels, and summarizes the commonly used construction technology of network covert channels. Then it analyzes the characteristics of the HTTP header lines and gives some methods of constructing network covert channels with these characteristics. Network covert channels based on the HTTP header lines are simple, flexible, and difficult to be detected and shielded.

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