Biblio

As a collection of innovative technologies, blockchain has solved the problem of reliable transmission and exchange of information on untrusted networks. The underlying implementation is the basis for the reliability of blockchain, which consists of various cryptographic algorithms for the use of identity authentication and privacy protection of distributed ledgers. The cryptographic algorithm plays a vital role in the blockchain, which guarantees the confidentiality, integrity, verifiability and non-repudiation of the blockchain. In order to get the most suitable cryptographic algorithm for the blockchain system, this paper proposed a method using Fuzzy Analytic Hierarchy Process (FAHP) to evaluate and score the comprehensive performance of the three types of cryptographic algorithms applied in the blockchain, including symmetric cryptographic algorithms, asymmetric cryptographic algorithms and hash algorithms. This paper weighs the performance differences of cryptographic algorithms considering the aspects of security, operational efficiency, language and hardware support and resource consumption. Finally, three cryptographic algorithms are selected that are considered to be the most suitable ones for block-chain systems, namely ECDSA, sha256 and AES. This result is also consistent with the most commonly used cryptographic algorithms in the current blockchain development direction. Therefore, the reliability and practicability of the algorithm evaluation pro-posed in this paper has been proved.

Cryptography is one of the important aspect of data and information security. The security strength of cryptographic algorithms rely on the secrecy and randomness of keys. In this study, bitwise operations, Fisher-Yates shuffling algorithm, and cipher text mapping are integrated in the proposed TRNG key generator for One-Time Pad cryptography. Frequency monobit, frequency within a block, and runs tests are performed to evaluate the key randomness. The proposed method is also evaluated in terms of avalanche effect and brute force attack. Tests results indicate that the proposed method generates more random keys and has a higher level of security compared with the usual OTP using PRNG and TRNGs that do not undergo a refining phase.

Unauthorized access of the data is one of the major threat for the real world digital data communication. Digital images are one of the most vital subset of the digital data. Several important and sensitive information is conveyed through digital images. Hence, digital image security is one of the foremost interest of the researchers. Cryptographic algorithms Biological sequences are often used to encrypt data due to their inherent features. DNA encryption is one of the widely used method used for data security which is based on the properties of the biological sequences. To protect the images from unwanted accesses, a new two stage method is proposed in this work. DNA Encryption and Polymerase Chain Reaction (PCR) Amplification is used to enhance the security. The proposed method is evaluated using different standard parameters that shows the efficiency of the algorithm.

The rapid growth of the connected devices driven by Internet of Things (IoT) concept requires a complete rethinking of the conventional approaches for the network design. One of the key constraints of the IoT devices are their low capabilities in order to optimize energy consumption. On the other hand, many IoT applications require high level of data protection and privacy, which can be provided only by advanced cryptographic algorithms, which are not feasible for IoT devices. In this paper, we propose a scalable quadrature modulation aiming to solve the problem of secure communications at the physical layer. The key idea of the proposed approach is to transmit only part of information in way that allows target receiver to retrieve the complete information. Such approach allows to ensure the security of wireless channel, while reducing the overhead of advanced cryptographic algorithms.

Nowadays one-time passwords are used in a lot of areas of information technologies including e-commerce. A few vulnerabilities in authentication protocols based on one-time passwords are widely known. In current work, we analyze authentication protocols based on one-time passwords and their vulnerabilities. Both simple and complicated protocols which are implementing cryptographic algorithms are reviewed. For example, an analysis of relatively old Lamport's hash-chain protocol is provided. At the same time, we examine HOTP and TOTP protocols which are actively used nowadays. The main result of the work are conclusions about the security of reviewed protocols based on one-time passwords.

The problem statement is that at present there is no stable algorithm which provides security for resource constrained devices because classic cryptography algorithms are too heavy to be implemented. So we will provide a model about the various cryptographic algorithms in this field which can be modified to be implement on constrained devices. The advantages and disadvantages of IOT devices will be taken into consideration to develop a model. Mainly IOT devices works on three layers which are physical layer, application and commutation layer. We have discuss how IOT devices individually works on these layers and how security is compromised. So, we can build a model where minimum intervention of third party is involved i.e. hackers and we can have higher and tight privacy and security system [1].we will discuss about the different ciphers(block and stream) and functions(hash algorithms) through which we can achieve cryptographic algorithms which can be implemented on resource constrained devices. Cost, safety and productivity are the three parameters which determines the ratio for block cipher. Mostly programmers are forced to choose between these two; either cost and safety, safety and productivity, cost and productivity. The main challenge is to optimize or balance between these three factors which is extremely a difficult task to perform. In this paper we will try to build a model which will optimize these three factors and will enhance the security of IOT devices.

Information security has become a major challenge in data transmission. Data transmitted through the network is vulnerable to many passive and active attacks. Cryptographic algorithms provide security against the data intruders and provide secure network communication. In this method, two algorithms TEA and DNA are combined to form a new algorithm called DETD (Double Encryption using TEA and DNA). The algorithm mainly deals with encryption and decryption time of a given input text. Here, both the encryption and decryption time are compared with the other two algorithms and the results are recorded. This algorithm also aims to provide data security by increasing the levels of encryption.

With the widespread of cloud computing, the delegation of storage and computing is becoming a popular trend. Concerns on data integrity, security, user privacy as well as the correctness of execution are highlighted due to the untrusted remote data manipulation. Most of existing proposals solve the integrity checking and verifiable computation problems by challenge-response model, but are lack of scalability and reusability. Via blockchain, we achieve efficient and transparent public verifiable delegation for both storage and computing. Meanwhile, the smart contract provides API for request handling and secure data query. The security and privacy issues of data opening are settled by applying cryptographic algorithms all through the delegations. Additionally, any access to the outsourced data requires the owner's authentication, so that the dat transference and utilization are under control.

When implemented on real systems, cryptographic algorithms are vulnerable to attacks observing their execution behavior, such as cache-timing attacks. Designing protected implementations must be done with knowledge and validation tools as early as possible in the development cycle. In this article we propose a methodology to assess the robustness of the candidates for the NIST post-quantum standardization project to cache-timing attacks. To this end we have developed a dedicated vulnerability research tool. It performs a static analysis with tainting propagation of sensitive variables across the source code and detects leakage patterns. We use it to assess the security of the NIST post-quantum cryptography project submissions. Our results show that more than 80% of the analyzed implementations have at least one potential flaw, and three submissions total more than 1000 reported flaws each. Finally, this comprehensive study of the competitors security allows us to identify the most frequent weaknesses amongst candidates and how they might be fixed.

Hardware implementations of cryptographic algorithms may leak information through numerous side channels, which can be used to reveal the secret cryptographic keys, and therefore compromise the security of the algorithm. Power Analysis Attacks (PAAs) [1] exploit the information leakage from the device's power consumption (typically measured on the supply and/or ground pins). Digital circuits consume dynamic switching energy when data propagate through the logic in each new calculation (e.g. new clock cycle). The average power dissipation of a design can be expressed by: Ptot(t) = α · (Pd(t) + Ppvt(t)) (1) where α is the activity factor (the probability that the gate will switch) and depends on the probability distribution of the inputs to the combinatorial logic. This induces a linear relationship between the power and the processed data [2]. Pd is the deterministic power dissipated by the switching of the gate, including any parasitic and intrinsic capacitances, and hence can be evaluated prior to manufacturing. Ppvt is the change in expected power consumption due to nondeterministic parameters such as process variations, mismatch, temperature, etc. In this manuscript, we describe the design of logic gates that induce data-independent (constant) α and Pd.

Data security has become an issue of increasing importance, especially for Web applications and distributed databases. One solution is using cryptographic algorithms whose improvement has become a constant concern. The increasing complexity of these algorithms involves higher execution times, leading to an application performance decrease. This paper presents a comparison of execution times for three algorithms using asymmetric keys, depending on the size of the encryption/decryption keys: RSA, ElGamal, and ECIES. For this algorithms comparison, a benchmark using Java APIs and an application for testing them on a test database was created.

In recent years, the chaos based cryptographic algorithms have enabled some new and efficient ways to develop secure image encryption techniques. In this paper, we propose a new approach for image encryption based on chaotic maps in order to meet the requirements of secure image encryption. The chaos based image encryption technique uses simple chaotic maps which are very sensitive to original conditions. Using mixed chaotic maps which works based on simple substitution and transposition techniques to encrypt the original image yields better performance with less computation complexity which in turn gives high crypto-secrecy. The initial conditions for the chaotic maps are assigned and using that seed only the receiver can decrypt the message. The results of the experimental, statistical analysis and key sensitivity tests show that the proposed image encryption scheme provides an efficient and secure way for image encryption.

Small embedded devices such as microcontrollers have been widely used for identification, authentication, securing and storing confidential information. In all these applications, the security and privacy of the microcontrollers are of crucial importance. To provide strong security to protect data, these devices depend on cryptographic algorithms to ensure confidentiality and integrity of data. Moreover, many algorithms have been proposed, with each one having its strength and weaknesses. This paper presents a Differential Power Analysis(DPA) attack on hardware implementations of Advanced Encryption Standard(AES) running inside a PIC18F2420 microcontroller.

Side Channel Attacks (SCA) using power measurements are a known method of breaking cryptographic algorithms such as AES. Published research into attacks on AES frequently target only AES-128, and often target only the core Electronic Code-Book (ECB) algorithm, without discussing surrounding issues such as triggering, along with breaking the initialization vector. This paper demonstrates a complete attack on a secure bootloader, where the firmware files have been encrypted with AES-256-CBC. A classic Correlation Power Analysis (CPA) attack is performed on AES-256 to recover the complete 32-byte key, and a CPA attack is also used to attempt recovery of the initialization vector (IV).

Educational software systems have an increasingly significant presence in engineering sciences. They aim to improve students' attitudes and knowledge acquisition typically through visual representation and simulation of complex algorithms and mechanisms or hardware systems that are often not available to the educational institutions. This paper presents a novel software system for CryptOgraphic ALgorithm visuAl representation (COALA), which was developed to support a Data Security course at the School of Electrical Engineering, University of Belgrade. The system allows users to follow the execution of several complex algorithms (DES, AES, RSA, and Diffie-Hellman) on real world examples in a step by step detailed view with the possibility of forward and backward navigation. Benefits of the COALA system for students are observed through the increase of the percentage of students who passed the exam and the average grade on the exams during one school year.
 

Theft or loss of a mobile device could be an information security risk as it can result in loss of con fidential personal data. Traditional cryptographic algorithms are not suitable for resource constrained and handheld devices. In this paper, we have developed an efficient and user friendly tool called “NCRYPT” on Android platform. “NCRYPT” application is used to secure the data at rest on Android thus making it inaccessible to unauthorized users. It is based on lightweight encryption scheme i.e. Hummingbird-2. The application provides secure storage by making use of password based authentication so that an adversary cannot access the confidential data stored on the mobile device. The cryptographic key is derived through the password based key generation method PBKDF2 from the standard SUN JCE cryptographic provider. Various tools for encryption are available in the market which are based on AES or DES encryption schemes. Ihe reported tool is based on Hummingbird-2 and is faster than most of the other existing schemes. It is also resistant to most of attacks applicable to Block and Stream Ciphers. Hummingbird-2 has been coded in C language and embedded in Android platform with the help of JNI (Java Native Interface) for faster execution. This application provides choice for en crypting the entire data on SD card or selective files on the smart phone and protect p ersonal or confidential information available in such devices.