Significant Bit Research Articles

On the Joint Optimization of Signal Constellations and Bit Mappings

On the Joint Optimization of Signal Constellations and Bit Mappings

Leaky Feeder as A VoIP Transmission Medium

VoIP (Voice over Internet Protocol) is a technology that allows its user to transmit voices using an internet network, although the technology uses the internet as its transmission medium VoIP still uses cable for most of its applications resulting in complicated cable management if not managed properly, this method can be optimized via wireless transmission for more efficient mobility and system configuration. This research aims to find out the capabilities of Leaky Feeder cable as a medium for VoIP transmission. A leaky feeder system consists of a single cable that runs along its designated space. This cable has gaps that allow the radio signal to leak into or out of the cable along its entire length meaning it can cover a larger area than the usual point-to-point transmission using cable. The parameters observed in particular are Signal Strength, Bit Rate, Packet Loss, Delay, and Throughput, the data obtained is taken quantitatively and its average value is calculated to ensure the system efficiency. Signal Strength trial shows an average value of -60.25 dBm, while also having an uplink and downlink of each 14.86 Mbps and 12.79 Mbps, Bit Rate trial shows that the more clients are served the less bandwidth each client will have , The Packet Loss trial shows an outstanding 0.71% loss, the delay trial shows an average of 20.5ms delay with -40dbm signal quality, and finally Throughput trial shows the highest value at 388Kbps when performing one call with -65dbm signal quality . This shows that the application of Leaky Feeder cable use on VoIP transmission is in a good category. Using Leaky Feeders in buildings can also reduce the number of Access Point installations required to cover the same area.

Content-Aware Selective Encryption for H.265/HEVC using Deep Hashing Network and Steganography

Existing selective encryption schemes for High Efficiency Video Coding (HEVC) only focus on the encoding characteristics of syntax elements in entropy coding and lack an understanding of the video content. Consequently, a large amount of unnecessary encryption operations are utilized to protect insensitive video frames, resulting in low encryption efficiency. In this paper, we propose a content-aware selective encryption scheme for H.265/HEVC, which encrypts only the groups of pictures (GOPs) containing sensitive content and thus offers high efficiency. In our scheme, a deep hashing network is first adopted to retrieve video frames to determine the content-sensitive GOPs. Then, multiple prediction and residual syntax elements in sensitive GOPs are encrypted using a keystream sequence generated by the hyperchaotic Lorenz system. In addition, the direct current coefficient of each \(4\times 4\) transform block is exchanged with a pseudo-randomly selected non-zero alternating current coefficient to further offer stronger visual distortion. Finally, the sign bits used for marking each GOP-type are reversibly embedded into the encrypted syntax elements to facilitate the decoder to distinguish the GOPs that need to be decrypted. Experimental results indicate that the proposed content-aware selective encryption scheme can efficiently protect sensitive content and is robust against all common attacks. Furthermore, it outperforms other state-of-the-art HEVC selective encryption algorithms in terms of security performance.

Information hiding using approximate POSIT representation

AbstractPOSIT is a numerical system consists of sign, regime, exponential, and fraction bits to overcome some limitations of the IEEE‐754 floating point (FP) representation. This work proposes a technique to hide critical information in the least significant bits (LSBs) of the POSIT FP representation by exploiting approximate computing (AC). The proposed technique, called information hiding using POSIT and LSB (IHUPL), explores the opportunities offered by both the POSIT representation and the AC to hide information with a minimum loss in accuracy and other performance metrics. IHUPL offers two options for hiding information: either by embedding one digit of each character into each pixel or by embedding all the digits of the character at the same time into each pixel of the alpha‐red, green, blue, or black/white image. Experimental results are evaluated for benchmark images and showed that IHUPL enhanced the accuracy of embedding data into LSB of POSIT FP by an average of 5%, the image quality improvement rates of IHUPL are 19% and 16% for options 1 and 2, respectively. Besides the encoding method using IHUPL, the paper outlines an extraction decoding technique that saves the original replacement bits in a key‐image to recover the hidden security message.

Design of modulated signal waveform in fully digital programmable optical frequency comb

AbstractThis paper presents a new design method of digital baseband signal for generating fully digital programmable optical frequency comb (OFC), which solves the problem of how to optimally select the digital baseband signal when OFC is generated by binary digital signal modulation. The inverse Fourier transform is used to study the waveform of binary digital signal which is used to generate OFC. It is found that the number of “0” bits of digital signal determines the flatness of comb lines. Based on this, a tunable ultra‐fine and ultra‐flat OFC was obtained by using a digital signal containing a large number of “0” bits in the experiment. This saves substantial computing time and resources compared to the current method of the k‐means clustering algorithm.

Methods of digital signature truncation for El-Gamal-type signatures and for DSTU 4145-2002.

Digital signature truncation is important for implementing cryptographic systems for low-resource devices, particularly in systems where signatures are stored for a long term but are checked relatively infrequently. Among such systems we can mention hardware audit logs or secure document repositories. Signature truncation can also be used in cases where memory is limited to represent or store the signature itself (for example, in QR codes). Signature truncation methods for ECDSA and EdDSA standards were proposed in public sources. This paper proposes a method of truncation of digital signatures for the classical El-Gamal scheme and some of its generalizations, which are based on modular arithmetic. The proposed methods do not require any alternations in the signing procedure, and are therefore applicable to arbitrary existing implementations of the El-Gamal scheme; the restoration of a digital signature occurs at the expense of an increase in computational costs on the part of the party verifying the signature. A digital signature truncation method for the national standard DSTU 4145-2002 is also proposed; this method takes into account the properties of the arithmetic of elliptic curves, on which the standard is based. The proposed methods make it possible to effectively implement the truncation of signatures of the El-Gamal type (especially noticeable for DSTU 4145-2002 signatures), discarding up to 32 bits of signature, but the complexity of the verification increases rapidly with the increase in the discarded part of the signature. However, for selected limits of the length of the discarded part, the proposed algorithms have a relatively efficient implementation and therefore can be used to reduce the length of signatures in protocols for low-resource devices.

Enabling ultra-high bit rate transmission with CFBG as dispersion compensator in an OptiSpan 240 km DWDM network

Abstract In this paper, a dispersion compensation technique for an ultra-long haul optical network utilizing a chirped fiber Bragg grating (CFBG) is presented. A high bit-rate signal of 40 Gbps is inputted into each channel. The CFBG, employed for dispersion compensation, is positioned after demultiplexing, enabling effortless network upgrades. The grating parameters of the implemented CFBG are mathematically analyzed and optimized to counteract net dispersion of over 3153 ps/nm across the channel. The design is verified using the OptiSystem software, resulting in a successful transmission up to 240 km with an average Q-factor of 8.09, utilizing an amplification gain of 49.5 dB. Additionally, the achieved optical signal-to-noise ratio (OSNR) level using the symmetrical amplification technique surpasses the acceptable value, with an average bit error rate of 10−16.

Beam Steering using Space-Time Modulated Coding Metasurface Based on Reconfigurable Plasma Ionization

This paper explores the use of space-time coding in beam steering, using 1-bit, 2-bit, and 3-bit reconfigurable coded meta-surfaces. By periodically changing the code arrangement in the time domain, a metasurface with code order in space and time is achieved. Selected codes are used to steer the beam in different directions for radar sensing systems applications. The phase of the harmonic signal is changed by controlling the position of different bits in each code sequence. The construction of 8×8 unit-cell elements (120×120×3.2 mm3) involves the use of a grounded dielectric container filled with inert-argon gas. The metasurface logic-state is controlled via the ionization degree of inert-gas with time-switching controlling the harmonic frequencies. Different time-switching sequences are investigated for beam steering. The proposed coding metasurface is analysed using CST Microwave Studio and the results are compared with the analytical solution using MATLAB.

Image security using steganography and cryptography with sweeping computational ghost imaging

A sweeping computational ghost imaging (SCGI)-based encryption system is intended for increased data security and speedier data transport. SCGI is combined with steganography and cryptography processes in this system. SCGI requires fewer shots, resulting in faster image capture, transmission, encryption, and decryption. This strategy also results in smaller, more compact data packages and higher bitrates. Least significant bit (LSB) uses steganography to conceal the hidden picture. In the case of Rivest–Shamir–Adleman (RSA) encryption, public and private keys are generated via a one-way function based on bucket values. Encryption is performed on two levels, with an asymmetric approach divided into three sub-items that significantly increase encryption. Surprisingly, the method uses fewer pictures for image reconstruction, resulting in faster image reconstruction. SCGI promises applications in an extensive number of data encryption sectors since this technology leads to smaller data packages and higher bitrates. The presented approach is examined using the number of pixel change rate (NPCR), normalized root mean square (NRMS), peak signal-to-noise ratio (PSNR), and correlation coefficient (CC), which indicates constant encryption improvement. We experimentally and situationally demonstrate our findings under eavesdropping, which prove the resistance and robustness of our methods. In optimal settings, this innovation enhances encryption by up to 90% when compared to traditional encryption methods.

Distributed arithmetic-FIR filter design using Approximate Karatsuba Multiplier and VLCSA

In this manuscript, a High Throughput and Low Latency DA-FIR filter design is integrated with Approximate Karatsuba Multiplier (AKM) and Variable Latency Carry Skip Adder (VLCSA) is proposed for the noise removal application in SDR. In this design, an AKM and VLCSA are considered to decrease the count of partial products on DA framework, although no multiplication is clearly performed. Thus, an important reduction is accomplished under accumulation circuits. The main execution problem of the DA system is the size of lookup table (LUT) increases exponentially through the length of inner product. To further diminish the memory complexity, approximate DA architectures depending truncation approach are needed. Partial products on DA are created through truncating least significant bits (LSBs) of inputs. The proposed hybrid technique lessens a count of LUTs by truncating the least significant bits of input operands. To further reduce the latency, this manuscript deals with one of the fastest multipliers, namely Approximate Karatsuba Multiplier employed for accumulation of partial products. The proposed design is performed in Verilog using Xilinx 14.5 ISE simulation. The experimental performances of the proposed DA-FIR-Hyb AKE-VLCSA filter is evaluated under lower delay, lower static power and compared with the existing filters.

Design of an Efficient & Secure Steganographic Model using Modified LSB & Encryption Process

This paper introduces a novel steganographic model for robust multimodal data security, seamlessly integrating a modified Least Significant Bit (LSB) technique with encryption, making it applicable to diverse data types such as images, audio, video, and text. Overcoming challenges posed by existing complex models and communication delays, our approach employs a modified LSB technique to encode similar sized data samples, followed by dynamic bioinspired elliptic curve cryptography (BECC) utilizing a Mayfly Optimization (MO) Model. This adaptive strategy optimizes curve types and prime key sets, significantly enhancing data security while minimizing delays and complexities across diverse data sizes. The proposed model achieves an 8.3% reduction in encryption and steganographic process delays, while simultaneously maintaining superior Peak Signal to Noise Ratio (PSNR) and lower Mean Squared Error (MSE) levels compared to existing methods when applied to the same data samples. This highlights its effectiveness in securing dynamic datasets without compromising efficiency.

A Reconfigurable Hybrid ADC Using a Jump Search Algorithm

This paper presents a reconfigurable hybrid Analog to Digital Converter (ADC) designed specifically for bio-signal processing, aiming to achieve low power consumption and high area efficiency. The proposed ADC utilizes a combination of 10-bit Most Significant Bit (MSB) Successive Approximation Register (SAR) and 2–4-bit Least Significant Bit (LSB) Single Slope (SS) architectures. The SS architecture incorporates the Dummy Capacitor Quantization Method (DCQM) which employs a 10-bit MSB dummy capacitor. This dummy capacitor can be configured to represent the 2-LSBs or reconstruct 4-LSBs. The reconfigurability of the ADC is achieved through the control of the reset timing of a 5-bit counter enabled by an external signal. The proposed ADC was fabricated using a Complementary Metal Oxide Semiconductor (CMOS) n-well 1-poly 8-metal process. Experimental measurements revealed that the ADC operates at a speed of 454 kS/s with power consumption of 18.7 μW. The Effective Number of Bits (ENoB) achieved by the ADC is 10.9 bits based on a 14-bit scale or 10.2 bits based on a 12-bit scale. The Figure of Merit (FoM) for the ADC is calculated to be 21.5 fJ/step for the 14-bit scale and 22.1 fJ/step for the 12-bit scale.

Analysis and Implementation of Blowfish and LSB Algorithm on RGB Images using SHA-512

The growth of the internet globally keeps increasing as time goes. There's a big amount of data type saved there too. Those data need to be secured so anyone who doesn't have the right to access them can access it. The purpose of this article is to secure text information into image media using the Blowfish method for encrypting text information and securing it using the Hash function SHA-512 and then embedded it in image media using the Least Significant Bit (LSB) method. The result of implementing those methods using image media sized 138Kb and 39.85Kb with plaintext measuring 27 and 85 characters shows that integrity data is secured with SHA-512 method. The test result using PSNR method to get the score of image quality after embedding information to the image shows that the average number of PSNR’s score is 70,74 dB which means the quality is good and has less difference from the original image.

High capacity double precision image steganography based on chaotic maps

Steganography is the process of hiding confidential information within non-secret multimedia such that the 3rd party cannot distinguish if there is a secret message in it or not. Whereas cryptography is the technique of using mathematical concepts to convert information into unreadable codes via a key. This paper will propose two approaches, lossless and lossy image steganography. Both of them will use cryptography and steganography based on three different chaotic maps to ensure information security. In the cryptography part, two chaotic maps will be used to encrypt the secret information, while in the steganography section, one chaotic map is used to embed the message. The secret information will be concealed in the least significant bits (LSBs) of the double-precision image’s pixels. The double precision image is a high-quality image and can be represented in 64 bits per pixel for grayscale images, leading to a very high redundant bit. Simulation results show a high embedding capacity of 60.938% and 400% for lossless and lossy approaches respectively with a peak signal to noise ratio (PSNR) reach of 69.964 dB. Furthermore, this system is extremely secure due to the use of 3 chaotic maps with key space 2448.

Message Encryption in Digital Images using the Zhang LSB Imange Method

Message encryption in digital images using the Zhang LSB Image method is a steganography technique that utilizes the Least Significant Bit (LSB) method to hide secret messages in the last bit of the image pixel. This method allows the use of images as a medium to convey hidden messages. The encryption process involves two main stages, namely message encryption and message hiding in an image. Message encryption is carried out using strong cryptographic algorithms to secure the authenticity and confidentiality of messages. Then, the encrypted message is inserted into the last bit of the image pixel using the LSB method. This is done by modifying the last bit value of the pixel so that the change is not visually visible to the human eye. To recover the original message, the message recovery process involves extracting the last bit of the modified image pixel and decrypting the message using the appropriate key. The Zhang LSB Image method is a steganography technique that is relatively simple but effective in hiding messages in digital images.

High-quality random bit generation based on a cascade-coupled nano-laser system

In this paper, a novel method is proposed to generate high-quality chaotic signals using three cascade-coupled nano-lasers (NLs), and generate high-speed, high-quality random number sequences. The master NL (MNL) is subjected to optical feedback, and its output is injected into the intermediate NL (INL), which is further injected into the slave NL (SNL). In the simulation, we first adjust proper parameters so that the SNL generates a chaotic signal with a large bandwidth and time-delay signature concealment. After performing self-delayed differential processing on the chaotic signal, and utilizing an 8-bit analog-to-digital converter for sampling and quantization, followed by extraction of the m-bits least significant bit, the final random bit sequence is obtained. Finally, we use NIST SP 800-22 to test the generated random numbers. The results demonstrate that the obtained random number sequence successfully passed all tests specified by NIST SP 800-22.

A CPW THz-MIMO antenna with reduced mutual coupling using Frequency Selective Surface for future wireless applications

In this article, we propose a novel THz-MIMO antenna system for future wireless applications. The performance of THz systems is prominently influenced by the MIMO configuration of the antenna. Increased signal attenuation and bit error rate (BER) are major hurdles to system performance at THz frequencies. MIMO antenna diversity techniques at the RF front end can significantly improve system performance. Toward this aim, this work attempts to develop a new THz-MIMO antenna system for future wireless applications. The proposed antenna uses a modified version of a traditional rectangular patch as the radiating element. The combination of a co-planar waveguide (CPW) feed structure and a modified stair-case radiator with an inverted L-shaped arch achieves excellent impedance matching between the feed line and the radiator, resulting in a broad bandwidth in the THz range. To evaluate the diversity performance of the antenna, both spatial and orthogonal 2-port antenna systems are designed and analyzed. Furthermore, isolation is enhanced by placing a frequency-selective surface (FSS) between the radiators of the proposed 4-port antenna. This design offers dual bandwidth, covering the ranges of 2.3–2.7 THz and 5.5–8.9 THz. The proposed antenna achieves very low mutual coupling (less than −30 dB), an extremely low envelope correlation coefficient (ECC) of 0.00001, and a low channel capacity loss (CCL) of 0.1 bps/Hz.

Secure most significant bit plane compression based reversible data hiding in encrypted image technique using Huffman Ciphersystem

Secure most significant bit plane compression based reversible data hiding in encrypted image technique using Huffman Ciphersystem

Radiation Detector Front-End Readout Chip with Nonbinary Successive Approximation Register Analog-to-Digital Converter for Wearable Healthcare Monitoring Applications.

A 16-channel front-end readout chip for a radiation detector is designed for portable or wearable healthcare monitoring applications. The proposed chip reads the signal of the radiation detector and converts it into digital serial-out data by using a nonbinary successive approximation register (SAR) analog-to-digital converter (ADC) that has a 1-MS/s sampling rate and 10-b resolution. The minimum-to-maximum differential and integral nonlinearity are measured as -0.32 to 0.33 and -0.43 to 0.37 least significant bits, respectively. The signal-to-noise-and-distortion ratio and effective number of bits are 57.41 dB and 9.24 bits, respectively, for an input frequency of 500 kHz and a sampling rate of 1 MS/s. The SAR ADC has a 38.9-fJ/conversion step figure of merit at the sampling rate of 1 MS/s. The proposed chip can read input signals with peak currents ranging from 20 to 750 μA and convert the analog signal into a 10-bit serial-output digital signal. The input dynamic range is 2-75 pC. The resolution of the peak current is 208.3 nA. The chip, which has an area of 1.444 mm × 10.568 mm, is implemented using CMOS 0.18-μm 1P6M technology, and the power consumption of each channel is 19 mW. This design is suitable for wearable devices, especially biomedical devices.

Secure and resilient improved image steganography using hybrid fuzzy neural network with fuzzy logic

The exponential growth in communication networks, data technology, advanced libraries, and mainly World Wide Web services has played a pivotal role in facilitating the retrieval of various types of information as needed. However, this progress has also led to security concerns related to the transmission of confidential data. Nevertheless, safeguarding these data during communication through insecure channels is crucial for obvious reasons. The emergence of steganography offers a robust approach to concealing confidential information, such as images, audio tracks, text files, and video files, in suitable media carriers. A novel technique is envisioned based on back-propagation learning. According to the proposed method, a hybrid fuzzy neural network (HFNN) is applied to the output obtained from the least significant bit substitution of secret data using pixel value differences and exploiting the modification direction. Through simulation and test results, it has been observed that the proposed methodology achieves secure steganography and superior visual quality. During the experiments, we observed that for the secret image of the cameraman, the PSNR & MSE values of the proposed technique are 61.963895 and 0.041361, respectively.