Block Of Bits Research Articles

Analysis of the Application of Logical Operations to Cryptographic Transformations of Information Security Means

In the article, the solution to the problem of determining logical operations that ensure cryptographic stability of the transformation of algorithms of cryptographic methods of information security is justified by the criterion of regularity - equal distribution"0" and "1" in the truth table. A logical operation with a truth table of uniform distribution of "0" and "1" and or blocks of bits has the property of cryptographic resistance.

Attacking (EC)DSA scheme with ephemeral keys sharing specific bits

In this paper, we present a deterministic attack on (EC)DSA signature scheme, providing that several signatures are known such that the corresponding ephemeral keys share a certain amount of bits without knowing their value. By eliminating the shared blocks of bits between the ephemeral keys, we get a lattice of dimension equal to the number of signatures having a vector containing the private key. We compute an upper bound for the distance of this vector from a target vector, and next, using Kannan's enumeration algorithm, we determine it and hence the secret key. The attack can be made highly efficient by appropriately selecting the number of shared bits and the number of signatures.

General rules of evaluating binary number divisibility on prime numbers

This research paper is to define new rule to find the divisibility of stream of binary on any prime numbers 3, 5, 7 …… with reminder 0. In general, the divisibility of binary numbers is most important in many digital circuits and mathematical applications. This paper explains this new rule for evaluating the divisibility of any binary number on any prime number greater than 2. This rule will depend on separating the binary number into blocks of bits then processes each block separately in a special procedure to find the possible divisibility on the prime number. After testing this new rule with prime numbers 3, 5, and 7 as a sample of prime numbers, the finding shows that this rule provides fast and true results.

Pilot-Based Unsourced Random Access With a Massive MIMO Receiver, Interference Cancellation, and Power Control

We consider the unsourced random access problem on a Rayleigh block-fading AWGN channel with multiple receive antennas. Specifically, we treat the slow fading scenario where the coherence blocklength is large compared to the number of active users and a message can be transmitted in a single fading coherence block. Unsourced random access refers to a form of grant-free random access where users are constrained to use the same codebook and therefore are a priori indistinguishable. The receiver must recover the list of transmitted messages up to permutations. In this paper, we propose an approach based on splitting the user messages into two parts. First, a small block of bits selects a relatively short codeword from a common “pilot” codebook. Then the remaining message bits are encoded by a standard block code for the Gaussian channel. The receiver makes use of a multiple measurement vector approximate message passing (MMV-AMP) algorithm to estimate the active user channels from the “pilot” part, and then uses the estimated channels to perform coherent maximum ratio combining (MRC) to decode the second part. We provide an accurate closed-form approximated analysis of the proposed scheme. Furthermore, we analyze the MRC decoding when successive interference cancellation is performed over groups of users, striking an attractive tradeoff between complexity and performance. Finally, we investigate the impact of power control policies, taking into account the unique nature of massive random access. As a byproduct, we also present an extension of the MMV-AMP algorithm which allows pathloss coefficients to be treated as deterministic unknowns by performing maximum likelihood estimation in each step of the MMV-AMP algorithm.

Secure and Sustainable Predictive Framework for IoT-Based Multimedia Services Using Machine Learning

In modern years, the Internet of Things (IoT) has gained tremendous growth and development in various sectors because of its scalability, self-configuring, and heterogeneous factors. It performs a vital role in improving multimedia communication and reducing production costs. The multimedia data consist of various types and formats (text, audio, videos, etc.), which are forwarded in the form of blocks of bits in the network layer of TCP/IP. Due to limited resources available to IoT-built devices, most of the Multimedia Internet of Things (MIoT)-based applications are delay constraints, especially for big data content. Similarly, multimedia-based applications are more vulnerable to security burdens and lower the trust of data processing. In this paper, we present a secure and sustainable prediction framework for MIoT data transmission using machine learning, which aims to offer intelligent behavior of the system with information protection. Firstly, the network edges exploit a regression analysis for a real-time multimedia routing scheme and achieve precise delivery towards the media servers. Secondly, an efficient and low-processing asymmetric process is proposed to provide secure data transmission between the IoT devices, edges, and data servers. Extensive experiments are performed over the OMNET++ network simulator, and its significance is achieved by an average for energy consumption by 71%, throughput by 30.5%, latency by 22%, bandwidth by 34.5%, packets overheads by 38.5%, computation time by 12.5%, and packet drop ratio by 35% in the comparison of existing schemes.

Spatial Jitter Influence on the Average BLER Performance of SIMO FSO Links over Atmospheric Turbulence Channels

In the recent years, Free Space Optics (FSO) technology has attracted significant research and commercial interest mostly because of its many advantages in comparison with other radio systems used for point-to-point connections. However, the reliable operation of these systems significantly depends on the conditions of the atmosphere in the area in which the optical beam propagates. The most important of these conditions are atmospheric turbulence and the misalignment between the optical beam and the receiver, which is also known as the pointing errors effect. In this work, in order to obviate the performance mitigation caused by these phenomena, we examined the most widely accepted and one of the most effective techniques, i.e., the implementation of receivers’ diversity. Various metrics have been investigated to evaluate the performance of such systems, but most of them do not take into account that the ultra-fast modern optical communication systems use blocks of bits for the transmission and codes for the detection and/or correction of erroneous bits. Thus, by taking these aspects into account, in this work, we investigated the combined impact of spatial jitter and atmospheric turbulence on the total average block error rate of an optical wireless system with receivers’ diversity. Novel closed-form analytical formulas were derived.

Cryptography with Analog Scheme Using Memristors

Networks of low-power Internet of Things do not have always access to enough computing power to support mainstream cryptographic schemes; such schemes also consume computing power that can be exposed to side channel attacks. This article describes a method, that we call “cryptography with analog scheme using memristors,” leveraging the physical properties of memristors, which are active elements suitable for the design of components such as artificial neurons. The proposed devices encrypt messages by segmenting them into blocks of bits, each modulating the injected currents into randomly selected memristor cells, resulting into sets of resistance values turned into cipher texts. Through hash-protected handshakes, identical addresses are independently generated by both communicating devices, to concurrently point at the same set of cells in the arrays, and their images. These block ciphers, for example, 1 KB long, can only be decrypted with the same memristor array driven by analog circuitry or its image, rather than digital key-based schemes. The proposed methods generate cipher text, and decrypt them, with approximately one femto joule per bit, which is below observable level through differential power analysis. The article explains how the use of different cells for each message to encrypt, driven under different conditions, has the potential to mitigate mainstream attacks. It provides a detailed characterization of memristors to evaluate the feasibility of the approach and discusses some hardware and architectures to implement the scheme.

Protecting Memories against Soft Errors: The Case for Customizable Error Correction Codes

As technology scales, radiation induced soft errors create more complex error patterns in memories with a single particle corrupting several bits. This poses a challenge to the Error Correction Codes (ECCs) traditionally used to protect memories that can correct only single bit errors. During the last decade, a number of codes have been developed to correct the emerging error patterns, focusing initially on double adjacent errors and later on three bit burst errors. However, as the memory cells get smaller and smaller, the error patterns created by radiation will continue to change and thus new codes will be needed. In addition, the memory layout and the technology used may also make some patterns more likely than others. For example, in some memories, there maybe elements that separate blocks of bits in a word, making errors that affect two blocks less likely. Finally, for a given memory, depending on the data stored, some error patterns may be more critical than others. For example, if numbers are stored in the memory, in most cases, errors on the more significant bits have a larger impact. Therefore, for a given memory and application, to achieve optimal protection, we would like to have a code that corrects a given set of patterns. This is not possible today as there is a limited number of code choices available in terms of correctable error patterns and word lengths. However, most of the codes used to protect memories are linear block codes that have a regular structure and which design can be automated. In this paper, we propose the automation of error correction code design for memory protection. To that end, we introduce a software tool that given a word length and the error patterns that need to be corrected, produces a linear block code described by its parity check matrix and also the bit placement. The benefits of this automated design approach are illustrated with several case studies. Finally, the tool is made available so that designers can easily produce custom error correction codes for their specific needs.

A New Security Framework for Cloud Data

In many organizations and institutions, the use of cloud has increased rapidly. Cloud data storage is one of the main advantages of cloud computing, where the data owners do not store their data on own servers, but the data are mainly stored on the cloud by the data owners. On this end, cloud security is one of the most analytical aspects due to the confidential information and responsive data. This paper presents a new security framework which provides more data security and confidentiality. In the new security framework, a data is spilt in the blocks of bits. Genetic algorithm is applied on every two blocks of bits. Final output of every genetic algorithm operation is a ciphertext which is also two blocks of bits. Each ciphertext is stored on cloud at distinct location and location of the ciphertext is not fixed. So, it is difficult for an attacker to detect where ciphertext is. Also, genetic algorithm has no key concept due to which security of data increases. The new security framework applies genetic algorithm on smaller block size which increases the security. The framework also uses the capability list for secure and fine grain access of data.

A Deterministic Analysis of Decimation for Sigma-Delta Quantization of Bandlimited Functions

We study Sigma-Delta ( $\Sigma \Delta $ ) quantization of oversampled bandlimited functions. We prove that digitally integrating blocks of bits and then down-sampling, a process known as decimation, can efficiently encode the associated $\Sigma \Delta $ bit-stream. It allows a large reduction in the bit-rate while still permitting good approximation of the underlying bandlimited function via an appropriate reconstruction kernel. Specifically, in the case of stable $r$ th order $\Sigma \Delta $ schemes we show that the reconstruction error decays exponentially in the bit-rate. For example, this result applies to the 1-bit, greedy, first-order $\Sigma \Delta $ scheme.

Efficient coding modulation and seamless rate adaptation for visible light communications

The past decade has witnessed a rapid development of VLC technologies. However, the spectral efficiency has to be improved and the robustness enhanced, especially in dynamic lighting conditions. This article proposes an analog rateless code (ARC) modulation scheme for VLC in a hybrid VLC-RF system. The ARC uses a variable-length low-density random projection matrix to map a block of bits into a virtually unlimited number of modulation symbols. The sender progressively transmits the symbols, which are jointly decoded at the receiver, until an acknowledgment of successful decoding is received. Both the protocol design and coding matrix generation are discussed. Simulations validate that our proposed scheme not only achieves the desired seamless rate adaptation, but significantly outperforms a traditional OFDM VLC system in spectrum efficiency. Furthermore, experimental results demonstrate the feasibility of the proposed ARC scheme in a VLC system.

A Novel and High Capacity Audio Steganography Algorithm Based on Adaptive Data Embedding Positions

In this study, a novel and high embedding capacity audio steganography scheme based on Lifting Wavelet Transform (LWT) and adaptive embedding positions is proposed. Specifically, the message data is inserted in the imperceptible positions that chosen from the coefficients of detail sub-bands taking advantage of our proposed Weighted Block Matching (WBM). The WBM is preceded by preparing the cover audio in order to select the bits-positions that can possibly be used for embedding from each detail coefficient based on coefficient amplitude then copy the contents of the selected bits-positions and arrange them in blocks of bits. Also, the message data is arranged in blocks of bits after preprocessed and encrypted. The WBM computes the matching between each message block and whole extracted cover blocks to find the similarity between them. This process help to provide optimal locations to hide the message blocks. These locations are considered as a stego-key that is ciphered and hided within the final detail sub-band which is specified for this purpose. The proposed approach attains higher security than other fixed embedding positions approaches because the random positions for the embedded message blocks based on adaptive selection for embedding positions. Experimental results show that the proposed technique is not only has very high embedding capacity (exceed 300 kbps) with excellent transparency (above 35 dB for the cover to noise ratio), but also achieve lossless massage retrieved. Comparisons with the related audio steganography algorithms also show that our proposed scheme outperforms all the selected algorithms.

A Study of SMR/TDMR With a Double/Triple Reader Head Array and Conventional Read Channels

Two-dimensional magnetic recording is a novel technology proposed to extend the life of conventional granular magnetic recording (CGMR). It is the readback counterpart technology to shingled magnetic recording (SMR) that is being pursued by the industry today. In SMR, a 2-D block of bits is written as a single unit: modifying any bit within the block requires a modification to the entire 2-D block. In TDMR, by comparison, a 2-D block is read and processed as a single unit. Latency during writing of a 2-D block is not a serious problem as the data is buffered in the RAM. Latency during readback, however, results in a performance degradation to the user who has to wait before getting his file. If there is a single reader head, 2-D readback necessitates multiple revolutions of the disk leading to a significant latency, which may not be acceptable to the user and is one of the reasons the industry is hesitating for 2-D magnetic recording (TDMR). Recent events have seen companies working on the development of multiple (two or three) reader heads that read multiple tracks simultaneously with a single pass of the head. Such double/triple reader head arrays could be used to support TDMR, obviating the need for multiple revolutions of the media and reducing the read latency. An alternative use for the multireader heads would be in an SMR scenario, where only a single track is readback at a time. In this case, the extra readers could be used to estimate and mitigate the intertrack interference coming from the adjacent tracks. The difference between these two modes is the number of tracks detected with each head pass. For TDMR there would be two or three tracks detected with a single pass while for SMR there would be just one. In this paper, we study and optimize the impact of parameters of the double/triple reader head array being used in the SMR and TDMR readback scenarios. The key difference between these scenarios is in the design of the GPR equalizer and we compare and contrast the recording system varying several key design parameters.

Single-Database Private Information Retrieval from Fully Homomorphic Encryption

Private Information Retrieval (PIR) allows a user to retrieve the ith bit of an n-bit database without revealing to the database server the value of i. In this paper, we present a PIR protocol with the communication complexity of O(γ logn) bits, where -y is the ciphertext size. Furthermore, we extend the PIR protocol to a private block retrieval (PBR) protocol, a natural and more practical extension of PIR in which the user retrieves a block of bits, instead of retrieving single bit. Our protocols are built on the state-of-the-art fully homomorphic encryption (FHE) techniques and provide privacy for the user if the underlying FHE scheme is semantically secure. The total communication complexity of our PBR is O(γ logm + γn/m) bits, where m is the number of blocks. The total computation complexity of our PBR is O(m logm) modular multiplications plus O(n=2) modular additions. In terms of total protocol execution time, our PBR protocol is more efficient than existing PBR protocols which usually require to compute O(n=2) modular multiplications when the size of a block in the database is large and a high-speed network is available.

Capacity Bounds and Concatenated Codes over Segmented Deletion Channels

We develop an information theoretic characterization and a practical coding approach for segmented deletion channels. Compared to channels with independent and identically distributed (i.i.d.) deletions, where each bit is independently deleted with an equal probability, the segmentation assumption imposes certain constraints, i.e., in a block of bits of a certain length, only a limited number of deletions are allowed to occur. This channel model has recently been proposed and motivated by the fact that for practical systems, when a deletion error occurs, it is more likely that the next one will not appear very soon. We first argue that such channels are information stable, hence their channel capacity exists. Then, we introduce several upper and lower bounds with two different methods in an attempt to understand the channel capacity behavior. The first scheme utilizes certain information provided to the transmitter and/or receiver while the second one explores the asymptotic behavior of the bounds when the average bit deletion rate is small. In the second part of the paper, we consider a practical channel coding approach over a segmented deletion channel. Specifically, we utilize outer LDPC codes concatenated with inner marker codes, and develop suitable channel detection algorithms for this scenario. Different maximum-a-posteriori (MAP) based channel synchronization algorithms operating at the bit and symbol levels are introduced, and specific LDPC code designs are explored. Simulation results clearly indicate the advantages of the proposed approach. In particular, for the entire range of deletion probabilities less than unity, our scheme offers a significantly larger transmission rate compared to the other existing solutions in the literature.

Enabling Efficient System Configurations for Dynamic Wireless Applications Using System Scenarios

Next generation mobile wireless systems (4G) support a wide range of communication protocols and services, thus opening new design challenges. The desired flexibility requires an effective utilization of system resources. In this article, we introduce the concept of system scenarios in wireless baseband engine signal processing optimization and in digital front-end power optimization. The scenario methodology classifies the system behavior from a cost perspective and provides the necessary information for an effective system tuning. We propose improvements for the clustering of the system executions into scenarios and the detection of scenarios at run time achieving a better trade-off between cost estimation accuracy and detection overhead. The first case study of the paper, using the WLAN communication protocol, demonstrates the accurate prediction of the execution time of each block of bits, which on average is 92 % shorter than the worst case allowing us to use the remaining time for the optimization of specifications like power consumption. In the second case study, we concentrate on the efficient signal power management during a WLAN transmission reducing the total energy consumption 50–94 % based on the throughput utilization.

A Block Cipher Algorithm for Multimedia Content Protection with Random Substitution using Binary Tree Traversal

Many people consume multimedia content (images, music, movie) on portable devices like DVD player, MP3 player, Portable Multimedia Player and also through Internet. Problem statement: The conventional algorithms such as DES and AES cannot be used directly in multimedia data, since multimedia data are repeatedly have high redundancy, large-volumes and require real-time operations, such as displaying, cutting, copying, bit-rate conversion and so forth. A block cipher is usually used to encrypt multimedia content because of its reasonable security and performance. Approach: In this study, we introduce a naive approach of efficient multimedia content encryption scheme which uses a block of bits rather than bytes or pixels. The proposed block cipher encrypts any type of compressed multimedia content by random substitution using binary tree traversal, row shifting and column shifting. Results: Experimental results show that the new algorithm has better performance than DES algorithm, encrypting multimedia content by dividing the plaintext by blocks. Conclusion: The proposed algorithm is implemented for all types of multimedia files like audio, video, images and text data and this algorithm can be used to multimedia data during transmisson through Internet or through any communication channels.

Carrier, Symbol and Block Synchronizers

The general PLL (Phase Lock Loop) is a device (LOOP) whose VCO (Voltage Controlled Oscillator) is able to follow (LOCK) the input signal phase (PHASE). However, the input signal can be a carrier regular sinusoidal wave, or a symbol/bit/data random stream, or a block of bits. So, in this direction, we have respectively the Carrier Synchronizer (CPLL), the Symbol Synchronizer (SPLL) and the Block Synchronizer (BPLL). The carrier synchronizer can be adapted as synthetizer of frequencies with different carriers. The symbol synchronizer recovers the clock of a synchronous system and can operate at different rhythms. The block synchronizer can produce streams of different bit rates. The three synchronizer prototypes can be adapted to different systems. Other objective is to study the output jitter UIRMS (Unit Interval Root Mean Square) versus input SNR (Signal noise ratio).

Improved distinguishers for HC-128

HC-128 is an eSTREAM final portfolio stream cipher. Several authors have investigated its security and, in particular, distinguishing attacks have been considered. Still, no one has been able to provide a distinguisher stronger than the one presented by Wu in the original HC-128 paper. In this paper we first argue that the keystream requirement in Wu's original attack is underestimated by a factor of almost 28. Our revised analysis shows that the keystream complexity of Wu's original attack is 2160.471 32-bit keystream blocks. We then go on to investigate two new types of distinguishers on HC-128. One of them, a distinguisher counting the number of zeros in created blocks of bits, gives a biased distribution that requires 2143.537 such constructed block samples (2152.537 32-bit keystream blocks). For fairness, the same metric is used to compare our attack to Wu's, and our improvement is significant compared to Wu's original result. Furthermore, the vector-based methodology used is general and can be applied to any cryptographic primitive that reveals a suitable probability distribution.

Variations on the Sensitivity Conjecture

The sensitivity of a Boolean function f of n Boolean variables is the maximum over all inputs x of the number of positions i such that flipping the i-th bit of x changes the value of f(x). Permitting to flip disjoint blocks of bits leads to the notion of block sensitivity, known to be polynomially related to a number of other complexity measures of f , including the decision-tree complexity, the polynomial degree, and the certificate complexity. A long-standing open question is whether sensitivity also belongs to this equivalence class. A positive answer to this question is known as the Sensitivity Conjecture. We present a selection of known as well as new variants of the Sensitivity Conjecture and point out some weaker versions that are also open. Among other things, we relate the problem to Communication Complexity via recent results by Sherstov (QIC 2010). We also indicate new connections to Fourier analysis.