MD5 Hash Function Research Articles

Signcryption with Matrix Modification of RSA Digital Signature Scheme and Cayley-Purser Algorithm


 The sender must ensure the security of messages and authenticated messages in messaging communications. Additionally, the sender must guarantee the message's integrity and cannot deny its authenticity or involvement with the message. This aspect is more robust because the recipient can verify, ensuring that the message originates from an authorized sender. In addition to this crucial aspect, the Signcryption method employing the Matrix Modification of RSA Digital Signature Scheme and the Cayley-Purser Algorithm can accomplish both of the objectives of this study. Encrypt-then-sign is the Signcryption method used, and the MD5 hash function performs one-way hashing during the signing procedure to enhance message security. This study tested the message plaintext in the form of a collection of strings consisting of uppercase (capital), lowercase (small), numbers (numeric), and other punctuation characters with varying numbers of characters in each string, as well as the value of modulus n from 10 digits up to its maximum length, which is unconstrained. The test results indicate that the time required for encryption and decryption is proportional to the number of plaintext characters used.

A Novel Hybrid Protocol and Code Related Information Reconciliation Scheme for Physical Layer Secret Key Generation

Wireless networks are vulnerable to various attacks due to their open nature, making them susceptible to eavesdropping and other security threats. Eavesdropping attack takes place at the physical layer. Traditional wireless network security relies on cryptographic techniques to secure data transmissions. However, these techniques may not be suitable for all scenarios, especially in resource-constrained environments such as wireless sensor networks and adhoc networks. In these networks having limited power resources, generating cryptographic keys between mobile entities can be challenging. Also, the cryptographic keys are computationally complex and require key management infrastructure. Physical Layer Key Generation (PLKG) is an emerging solution to address these challenges. It establishes secure communication between two users by taking advantage of the wireless channel's inherent features. PLKG process involves channel probing, quantization, information reconciliation (IR) and privacy amplification to generate symmetric secret key. The researchers have used various PLKG techniques to get the secret key, sTop of Form
 till they face problems in the IR scheme to obtain symmetric keys between the users who share the same channel for communication. Both the code based and protocol based methods proposed in the literature have advantages and limitations related to their performance parameters such as information leakage, interaction delay and computation complexity. This research work proposes a novel IR mechanism that combines the protocol and code-based error correction methods to obtain reduced Bit Mismatch Rate (BMR), reduced information leakage, reduced interaction delay, and reduced computational time to enhance physical layer secret key's quality. In the proposed research work, the channel samples are generated using the Received Signal Strength (RSS) and Channel Impulse Response (CIR) parameters. These samples are quantized using Vector Quantization with Affinity Propagation Clustering (VQAPC) method to generate the preliminary key. The samples collected by the two users who wish to communicate, (for example Alice and Bob) will be different due to noise in the channel and hardware limitations. Hence their preliminary keys will be different. Removing this discrepancy between Bob's and Alice's initial keys, using novel Hybrid Protocol and Code related Information Reconciliation (HPC-IR) scheme to generate error corrected key, is the most important contribution of this research work. This key is further encoded by the MD5 hash function to generate a final secret key for exchanging information between two users over the wireless channel. It is observed that the proposed HPC-IR scheme achieves BMR of 19.4%, information leakage is 0.002, interaction delay is 0.001 seconds and computation time is 0.02 seconds.

Analyzing execution path non-determinism of the Linux kernel in different scenarios

Safety-critical systems play a significant role in industrial domains, and their complexity is increasing with advanced technologies such as Artificial Intelligence (AI). To provide efficient services, safety-critical systems that integrate AI applications are always built based on Linux, where Linux offers massive amounts of features and an incredibly perfect software ecosystem for AI applications. Since Linux is a pre-existing complex software system, different research programmes aim to pave the way for developing Linux-based safety-critical systems. Still, only some focus on the system calls for file operations. However, the execution path of a system call is effectively non-deterministic in Linux kernel space, which challenges the test coverage-based verification recommended by the functional safety standards. This research analyzes the influence of system state on Linux kernel path variability from two perspectives: file system type and system load. Therefore, an online data collection system for system call execution paths was constructed based on Ftrace, network file system (NFS), and MD5 hash function, uniquely identifying the system call execution path. The collected data were processed and analysed in this study. Evaluations show that the number of function execution paths of the system calls relevant to file systems increased with the increase in system load but would eventually be stable. Additionally, the function execution paths of the system call varied in different file systems. Based on the evaluations, the results of this work can provide advice for analyzing Linux-based safety-critical systems. In addition, the method introduced in this research can also provide support for the verification of Linux-based safety-critical systems.

Incorporating Prior Knowledge in Local Differentially Private Data Collection for Frequency Estimation

Local differential privacy (LDP) is a prevalent measure of privacy protection as it provides rigorous privacy guarantees and has been widely studied for statistical analysis, especially in frequency estimation. As a representative LDP-enabled frequency estimation algorithm, Google's <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Randomized Aggregation Privacy-Preserving Ordinal Response</i> (RAPPOR) has been put into practice. However, it achieves sub-optimal utility due to the following limitations. Firstly, the adoption of the MD5 hash function inevitably results in the hash collision. Secondly, the application of the randomized response technique leads to randomness. To improve the practical effectiveness of RAPPOR and the utility of frequency-based services, we propose an LDP-enabled frequency estimation method called PK-RAPPOR, in which we devise an effective re-encoding hash function (RE-HF) incorporating prior knowledge (PK) about the rough frequency ranking of items. RE-HF divides items into several cohorts based on the PK and generates a unique hash value set for each item. Compared with the original RAPPOR, the hash collision can be eliminated for items from different cohorts, and the effect of randomness can be decreased by the overlapping of items from the same cohorts. We validate our proposed method with theoretical analysis and demonstrate its effectiveness with experiments on both synthetic and real-world datasets.

A Secure Data Transfer Approach With an Efficient Key Management Over Cloud

The growth in the number of cloud users who transfer their health data have enhanced the importance of cloud technology's services and capabilities. However, transferring patient health data to the cloud leaves researchers with several concerns and obstacles in privacy, storage, access, key-formation, and management. The paper presents an efficient methodology for storing and accessing health information to and from the cloud. The symmetric key cryptography with the MD5 hash function is employed to enhance the framework's efficiency. The proposed method also provides secure data sharing and removes the burden of an exhaustive re-encryption computation. In the paper, two different keys are computed: one key for each legitimate user among a group and another key for the crypto-system, which is responsible to do all computations over the data. The method provides security against internal threats since only a single share of the key can be accessed. The efficiency of the model is measured by measuring the execution time for key formation, encryption, and decryption processes.

A Dynamic Light-Weight Symmetric Encryption Algorithm for Secure Data Transmission via BLE Beacons

Pervasive sensing with Body Sensor Networks (BSNs) is a promising technology for continuous health monitoring. Since the sensor nodes are resource-limited, on-node processing and advertisement of digested information via BLE beacon is a promising technique that can enable a node gateway to communicate with more sensor nodes and extend the sensor node’s lifetime before requiring recharging. This study proposes a Dynamic Light-weight Symmetric (DLS) encryption algorithm designed and developed to address the challenges in data protection and real-time secure data transmission via message advertisement. The algorithm uses a unique temporal encryption key to encrypt each transmitting packet with a simple function such as XOR. With small additional overhead on computational resources, DLS can significantly enhance security over existing baseline encryption algorithms. To evaluate its performance, the algorithm was utilized on beacon data encryption over advertising channels. The experiments demonstrated the use of the DLS encryption algorithm on top of various light-weight symmetric encryption algorithms (i.e., TEA, XTEA, PRESENT) and a MD5 hash function. The experimental results show that DLS can achieve acceptable results for avalanche effect, key sensitivity, and randomness in ciphertexts with a marginal increase in the resource usage. The proposed DLS encryption algorithm is suitable for implementation at the application layer, is light and energy efficient, reduces/removes the need for secret key exchange between sensor nodes and the server, is applicable to dynamic message size, and also protects against attacks such as known plaintext attack, brute-force attack, replaying attack, and differential attack.

Reversible and Plausibly Deniable Covert Channels in One-Time Passwords Based on Hash Chains

Covert channels enable stealthy communications over innocent appearing carriers. They are increasingly applied in the network context. However, little work is available that exploits cryptographic primitives in the networking context to establish such covert communications. We present a covert channel between two devices where one device authenticates itself with Lamport’s one-time passwords based on a cryptographic hash function. Our channel enables plausible deniability jointly with reversibility and is applicable in different contexts, such as traditional TCP/IP networks, CPS/IoT communication, blockchain-driven systems and local inter-process communications that apply hash chains. We also present countermeasures to detect the presence of such a covert channel, which are non-trivial because hash values are random-looking binary strings, so that deviations are not likely to be detected. We report on experimental results with MD5 and SHA-3 hash functions for two covert channel variants running in a localhost setup. In particular, we evaluate the channels’ time performance, conduct statistical tests using the NIST suite and run a test for matching hash values between legitimate and covert environments to determine our channels’ stealthiness.

Manajemen Pengelolaan Bukti Digital Untuk Meningkatkan Aksesibilitas Pada Masa Pandemi Covid-19

Covid-19 has a major impact on human life, including the process of managing digital evidence. Management of digital evidence requires special handling that can store and maintain the integrity of digital evidence. The current problem is there is no concept of storing digital evidence that can be accessed online in wider accessibility. Online digital evidence management is proposed as a solution to solve this problem. This concept is in the form of an online digital evidence management system that can be accessed anywhere and anytime using MD5 and SHA1 hash functions in order to maintain the properties of digital evidence so that it can be legally accepted. The problems with digital evidence management require a Management System for Digital Evidence that is suitable for application in Digital Forensics Laboratory. This research had successfully implemented the concept of online chain of custody. It is expected, with the concept of Online Digital Evidence Management, this digital evidence control and all activities related to it can be maintained and well documented. Moreover, it can reach a wider area accessed anywhere and any time and reduce the spread of Covid-19.

A novel triple recovery information embedding approach for self-embedded digital image watermarking

Image tamper detection and recovery has become an important issue in recent years. In order to detect and recover high tampering rated images, this paper presents a novel self-embedded fragile watermarking method with triple recovery information embedding approach. In this proposed method host image is divided into sixteen main blocks. Four partner blocks are selected from main blocks as a partner group using Look-Up table which is constructed for recovery against high tampering rated images. Each partner block is divided into 4 × 4 blocks. Recovery data of each partner block is generated from the mean values of the 4 × 4 blocks. Then, triple recovery information for each partner block is constructed by combining recovery data of the three other partner blocks. After the generation of the recovery information, each partner block is divided into 16 × 16 blocks. Then, these blocks are divided into four 8 × 8 sub-blocks. Recovery bits for each partner block are embedded into the first and second least significant bits (LSBs) of the first three sub-blocks. It means that triple copies of recovery information for each partner block are embedded into three other blocks in the image, which provides triple chance for recovery of the tampered areas. On the other hand, authentication information is generated from the pixels of the 16 × 16 recovery information embedded image blocks by using MD5 hash function. This authentication information is embedded into the quarter part of each 16 × 16 block by using LSB substitution. The performance of the proposed method has been demonstrated by applying different size of cropping attacks to the different areas of the watermarked images. Experimental results show that the proposed method satisfactory recovers up to 75% tampering rated images.

A Novel Improvement With an Effective Expansion to Enhance the MD5 Hash Function for Verification of a Secure E-Document

MD5 is a one-way cryptographic function used in various fields for maintaining data integrity. The application of a Hash function can provide much protection and privacy and subsequently reduce data usage. Most users are familiar with validating electronic documents based on a Hash function, such as the MD5 algorithm and other hash functions, to demonstrate the data integrity. There are many weaknesses of the current MD5 algorithm, mainly its failures and weaknesses against varying types of attacks, such as brute force attacks, rainbow table attacks, and Christmas attacks. Therefore, the method proposed in this paper enhances the MD5 algorithm by adding a dynamic variable length and a high efficiency that simulates the highest security available. Whereas the logistic system was used to encode ribonucleic acid (RNA) by generating a random matrix based on a new key that was created using the initial permutation (IP) tables used in the data encryption stander (DES) with the linear-feedback shift register (LFSR), this work proposes several structures to improve the MD5 hash function. The experimental results demonstrate its high resistance to hackers while maintaining a suitable duration. This paper discusses the design of a confident hash algorithm. This algorithm has characteristics that enable it to succeed in the field of digital authentication and data integrity.

Hybrid Encryption Algorithm to Detect Clone Node Attack in Wireless Sensor Network

Wireless sensor network (WSN) is the collection of sensor nodes which are distributed in a specific environment. WSN is resource-controlled network which is vulnerable to physical attacks i.e. clone node attack. An attacker acquires information from captured node and then creates the cloned node in the WSN. The main purpose of the cloned nodes is to control the entire network and increase the invasion in the sensor network. When communicating from legitimate node to other node, the message is not secure, so an attacker can modify it. Current asymmetric encryption methods and symmetric encryption methods can provide a level of security, but there are some limitations in it. The hybrid encryption method combining the asymmetric and symmetric methods which will offers high security with minimal key management. We have proposed a new hybrid secure encryption method in this paper which combines the asymmetric and symmetric cryptography method. The proposed efficient algorithm to protect communication from clone node attacks in wireless sensor network. The hybrid algorithm uses advanced cryptographic standards AES, BSDN and Dual RSA encryption techniques and MD5 hash functions. In this algorithm, message is divided into three parts and BSDN, AES and Dual RSA encryption are parallel implemented to the sub-message. The proposed algorithm is analyzed based on parameters such as encryption, decryption and execution time. The result shows that proposed encryption algorithm works better in terms of encryption and decryption time.

A novel image encryption algorithm based on bit-plane matrix rotation and hyper chaotic systems

In this paper, we propose a new image encryption algorithm based on bit-plane matrix rotation and two hyper chaotic systems. The algorithm first decomposes the plain-image into eight bit planes and constructs a three-dimensional (3D) matrix. Then the sub-matrix of the 3D bit-plane matrix is rotated in different directions controlled by PRNS generated by a hyper-chaotic system. Finally, the pixel values of the intermediate image are modified by using another key stream. Furthermore, the initial values of diffusion and parameters related with generating chaotic sequences are produced by the MD5 hash function of the plain-image, which enhances the correlation between the encryption process and the plain-image. Simulation experiments are presented to analyze the image encryption scheme in terms of key space, histogram, information entropy, key sensitivity and adjacent pixels correlation index. Theoretical analysis and experimental results demonstrate that the proposed algorithm has excellent performance and suffcient security level.

A Tamper Proofing Text Watermarking Shift Algorithm for Copyright Protection

Watermarking has proved its great reliability and flexibility for property rights protection and tamper detection of diverse forms of online distributed data. Among the different mediums in which watermarking technology is used, text watermarking represents the most challenging issue due to the distinctive nature of its various formats. Plain text is widely used for transferring information on the internet. Despite this, there is a lack of used plain text watermarking techniques, so obviously it’s necessary to focus on that point and pay it more attention. In this paper a blind text watermarking approach is proposed for copyright protection and tamper detection of plain text by inter-word spacing (depending on a secret binary number and a key word) and text fingerprint through using MD5 hash function. Simulation results proved the success of our approach in detecting any tiny content tampering and due to the secret key and the fingerprint of watermarked text copyright protection are accomplished efficiently. This approach is a combination of several steps which work cooperatively to reach the desired goals.

E-mail recovery from websites using Gravatar

Although the Internet has not been created for anonymity, many users posting comments on blogs hope that they will remain anonymous. The article presents an attack on revealing the e-mail addresses of users posting comments on the sample website using Gravatar. This attack aims to make readers aware of the fact that by posting comments on sites using Gravatara services, we are exposed to the disclosure of our e-mail addresses and sometimes even of our real identity. Keywords: Gravatar, deanonimization, e-mail, MD5 hash function

A research on the impact of encryption algorithms on the quality of VPN tunnels’ transmission

The following article presents the results on the impact of encryption algorithms and the cryptographic hash function on the QoS (Quality of Service) transmission in a computer network. A network model supporting data encryption using the AES algorithm and the MD5 and SHA hash functions used in VPN tunnels was designed and tested. The influence of different data length on the quality of transmission in a secured network was studied. The measurements and tests of networks were performed according to two methodologies ITU-T Y.1564 and RFC 2544. The impact of the data encryption mechanism on bandwidth, data loss and maximum delays was examined. The secured network tests were performed with different combinations of encryption algorithms and hash functions of the VPN tunnel in the ESP (Encapsulating Security Payload) transport mode.

Binocular visual characteristics based fragile watermarking scheme for tamper detection in stereoscopic images

In the past decade, various fragile digital watermarking techniques have been proposed for monoscopic image authentication and temper detection. In this paper, a novel binocular visual characteristics based pixel-wise fragile watermarking scheme for stereoscopic image authentication and tamper detection is proposed. The scheme consists of two processes: embedding of the stereoscopic image authentication message and tamper detection. In the watermark embedding process, the binocular just noticeable difference (BJND) model is used for guiding watermark embedding, which is convenient for achieving a balanced relationship between watermarking capacity and visual transparency. In the tamper detection process, a probability theory and an algorithm of binocular disparity are employed to improve previously obtained detection results and to enhance authentication accuracy. Moreover, to improve the security of the proposed scheme, MD5 hash function and chaotic map are used. Experimental results reveal that the proposed scheme is not only secure, but also achieves superior tamper detection for different attacks.

Parallel chaotic hash function based on the shuffle-exchange network

In recent years, cryptologists have been delving into chaos theory to design more secure cryptographic primitives. However, many existing chaos-based algorithms are slow due to floating point operations. They are mostly sequential in nature and therefore cannot take advantage of multicore processors for faster speed. In this paper, a new chaos-based hash function is proposed that utilizes multiple instances of chaotic maps that run in parallel to improve hashing speed. Parallelization is realized using the baseline network that also strengthens the security of the hash function due to its shuffling mechanism. The combination of linear and nonlinear chaotic maps is used to provide a high level of sensitivity to initial conditions, confusion and diffusion characteristics as well as strong collision resistance. Results show that the proposed design has strong security strength with near-perfect statistical qualities and fast hashing speed that surpasses both chaotic hash functions and the MD5 hash function.

SHA-1 and MD5 Cryptographic Hash Functions: Security Overview

Despite their obsolescence and recommendations they are phased out from production environment, MD5 and SHA-1 cryptographic hash functions remain defaults frequently offered in many applications, e.g., database managers. In the article, we present a security overview of both algorithms and demonstrate the necessity to abandon them in favor of more resilient alternatives due to low computational requirements necessary to reverse engineer the message digests, or to future proof security due to advances in hardware performance and scalability. Suitability procedures and their methods of use are part of this article.

Исследование криптостойкости протокола аутентификации BotikKey к компрометации уязвимостей алгоритма хеширования MD5

Исследование криптостойкости протокола аутентификации BotikKey к компрометации уязвимостей алгоритма хеширования MD5

Securing Bluetooth Communication with Hybrid Pairing Protocol

To improve the level of security of Bluetooth communication, a hybrid pairing protocol based on Diffie-Hellman Key Exchange protocol, MD5 and Hummingbird-2 is proposed. The developed hybrid pairing protocol adopted the DH Key agreement protocol to securely compute both parties’ shared secret key. MD5 hash function is used to solve the problem(s) caused by having a short PIN. This mechanism is integrated with the Hummingbird-2, a lightweight encryption algorithm, to further strengthen the pairing mechanism and at the same time, making it suitable for devices that has limited processing power and memory. This hybrid pairing protocol is expected to increase the security of the Bluetooth devices against known attacks, such as man-in-the-middle attack and eavesdropping, by combining these strong yet lightweight algorithms.