Biblio

In this work, we examine the following question: How can we improve the best data complexity among the impossible differential (ID) attacks on AES? One of the most efficient attacks on AES are ID attacks. We have seen that the Biham-Keller ID characteristics are frequently used in these ID attacks. We observe the following fact: The probability that a given pair with a wrong key produce an ID characteristic is closely correlated to the data usage negatively. So, we maximize this probability by exploiting a Biham-Keller ID characteristic in a different manner than the other attacks. As a result, we mount an ID attack on 7-round AES-192 and obtain the best data requirement among all the ID attacks on 7-round AES. We make use of only 2$^\textrm58$ chosen plaintexts.

Scan-based test methodology is one of the most popular test techniques in VLSI circuits. This methodology increases the testability which in turn improves the fault coverage. For this purpose, the technique uses a chain of scan cells. This becomes a source of attack for an attacker who can observe / control the internal states and use the information for malicious purposes. Hence, security becomes the main concern in the Integrated Circuit (IC) domain since scan chains are the main reason for leakage of confidential information during testing phase. These leakages will help attackers in reverse engineering. Measures against such attacks have to be taken by encrypting the data which flows through the scan chains. Lightweight ciphers can be used for scan chain encryption. In this work, encryption of scan data is done for ISCAS-89 benchmarks and the performance and security properties are evaluated. Lightweight stream and block ciphers are used to perform scan encryption. A comparative analysis between the two techniques is performed in par with the functions related to design cost and security properties.

All along, white-box cryptography researchers focus on the design and implementation of certain primitives but less to the practice of the cipher working modes. For example, the Galois/Counter Mode (GCM) requires block ciphers to perform only the encrypting operations, which inevitably facing code-lifting attacks under the white-box security model. In this paper, a code-lifting resisted GCM (which is named WBGCM) is proposed to mitigate this security drawbacks in the white-box context. The basic idea is to combining external encodings with exclusive-or operations in GCM, and therefore two different schemes are designed with external encodings (WBGCM-EE) and maskings (WBGCM-Maksing), respectively. Furthermore, WBGCM is instantiated with Chow et al.'s white-box AES, and the experiments show that the processing speeds of WBGCM-EE and WBGCM-Masking achieves about 5 MBytes/Second with a marginal storage overhead.

The cryptology science has gradually gained importance with our digitalized lives. Ensuring the security of data transmitted, processed and stored across digital channels is a major challenge. One of the frequently used components in cryptographic algorithms to ensure security is substitution-box structures. Random selection-based substitution-box structures have become increasingly important lately, especially because of their advantages to prevent side channel attacks. However, the low nonlinearity value of these designs is a problem. In this study, a dataset consisting of twenty different substitution-box structures have been publicly presented to the researchers. The fact that the proposed dataset has high nonlinearity values will allow it to be used in many practical applications in the future studies. The proposed dataset provides a contribution to the literature as it can be used both as an input dataset for the new post-processing algorithm and as a countermeasure to prevent the success of side-channel analyzes.

Lightweight cryptography concept has been a very hot topic for the last few years and considered as a new domain of encryption suitable for big data networks, small devices, phones, cards and embedded systems. These systems require low latency security and low power consuming [1]. An improved lightweight encryption algorithm ILEA is proposed in this paper. ILEA is based on PRINCE lightweight algorithm as his main core with two defacing balanced mixing layers added. ILEA presented in two programming languages: PYTHON, C++ with a comparative study with original PRINCE results and some of another lightweight algorithms.

Lightweight cryptography is a new branch of cryptography focused on providing security to resource-constraint devices such as wireless sensor networks (WSN), Radio-Frequency Identification (RFIDs) and other embedded systems. The factors considered in lightweight cryptography are mainly circuit area, memory requirement, processing time, latency, power, and energy consumption. This paper presents a discussion on common lightweight block ciphers in terms of different performance parameters, strength, design trends, limitations, and applications including the National Institute of Science and Technology (NIST) round 1 and 2 candidates. Analysis of these lightweight algorithms has offered an insight into this newly emerging field of cryptography.

In most applications, security attributes are pretty difficult to meet but it becomes even a bigger challenge when talking about Grid Computing. To secure data passes in Grid Systems, we need a professional scheme that does not affect the overall performance of the grid system. Therefore, we previously developed a new security scheme “ULTRA GRIDSEC” that is used to accelerate the performance of the symmetric key encryption algorithms for both stream and block cipher encryption algorithms. The scheme is used to accelerate the security of data pass between elements of our newly developed pure peer-to-peer desktop grid framework, “HIMAN”. It also enhances the security of the encrypted data resulted from the scheme and prevents the problem of weak keys of the encryption algorithms. This paper covers the analysis and evaluation of this scheme showing the different factors affecting the scheme performance, and covers the efficiency of the scheme from the security prospective. The experimental results are highlighted for two types of encryption algorithms, TDES as an example for the block cipher algorithms, and RC4 as an example for the stream cipher algorithms. The scheme speeds up the former algorithm by 202.12% and the latter one by 439.7%. These accelerations are also based on the running machine's capabilities.

The economic progress of the Internet of Things (IoT) is phenomenal. Applications range from checking the alignment of some components during a manufacturing process, monitoring of transportation and pedestrian levels to enhance driving and walking path, remotely observing terminally ill patients by means of medical devices such as implanted devices and infusion pumps, and so on. To provide security, encrypting the data becomes an indispensable requirement, and symmetric encryptions algorithms are becoming a crucial implementation in the resource constrained environments. Typical symmetric encryption algorithms like Advanced Encryption Standard (AES) showcases an assumption that end points of communications are secured and that the encryption key being securely stored. However, devices might be physically unprotected, and attackers may have access to the memory while the data is still encrypted. It is essential to reserve the key in such a way that an attacker finds it hard to extract it. At present, techniques like White-Box cryptography has been utilized in these circumstances. But it has been reported that applying White-Box cryptography in IoT devices have resulted in other security issues like the adversary having access to the intermediate values, and the practical implementations leading to Code lifting attacks and differential attacks. In this paper, a solution is presented to overcome these problems by demonstrating the need of White-Box Cryptography to enhance the security by utilizing the cipher block chaining (CBC) mode.

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.

The recent development of IoT technologies and cloud storages, many types of information including private information have been gradually outsourced. For such a situation, new convenient functionalities such as arithmetic and keyword search on ciphertexts are required to allow users to retrieve information without leaking any information. Especially, searchable encryptions have been paid much attention to realize a keyword search on an encrypted domain. In addition, an architecture of searchable symmetric encryption (SSE) is a suitable and efficient solution for data outsourcing. In this paper, we focus on an SSE scheme which employs a secure index for searching a keyword with optimal search time. In the conventional studies, it has been widely considered that the scheme searches whether a queried keyword is contained in encrypted documents. On the other hand, we additionally take into account the location of a queried keyword in documents by targeting a matrix-type data format. It enables a manager to search personal information listed per line or column in CSV-like format data.

Distinguishing analysis is an important part of cryptanalysis. It is an important content of discriminating analysis that how to identify ciphertext is encrypted by which cryptosystems when it knows only ciphertext. In this paper, Fisher's discriminant analysis (FDA), which is based on statistical method and machine learning, is used to identify 4 stream ciphers and 7 block ciphers one to one by extracting 9 different features. The results show that the accuracy rate of the FDA can reach 80% when identifying files that are encrypted by the stream cipher and the block cipher in ECB mode respectively, and files encrypted by the block cipher in ECB mode and CBC mode respectively. The average one to one identification accuracy rates of stream ciphers RC4, Grain, Sosemanuk are more than 55%. The maximum accuracy rate can reach 60% when identifying SMS4 from block ciphers in CBC mode one to one. The identification accuracy rate of entropy-based features is apparently higher than the probability-based features.

In this work, a quantum design for the Simplified-Advanced Encryption Standard (S-AES) algorithm is presented. Also, a quantum Grover attack is modeled on the proposed quantum S-AES. First, quantum circuits for the main components of S-AES in the finite field F2[x]/(x4 + x + 1), are constructed. Then, the constructed circuits are put together to form a quantum version of S-AES. A C-NOT synthesis is used to decompose some of the functions to reduce the number of the needed qubits. The quantum S-AES is integrated into a black-box queried by Grover's algorithm. A new approach is proposed to uniquely recover the secret key when Grover attack is applied. The entire work is simulated and tested on a quantum mechanics simulator. The complexity analysis shows that a block cipher can be designed as a quantum circuit with a polynomial cost. In addition, the secret key is recovered in quadratic speedup as promised by Grover's algorithm.

We propose a new class of post-quantum digital signature schemes that: (a) derive their security entirely from the security of symmetric-key primitives, believed to be quantum-secure, and (b) have extremely small keypairs, and, (c) are highly parameterizable. In our signature constructions, the public key is an image y=f(x) of a one-way function f and secret key x. A signature is a non-interactive zero-knowledge proof of x, that incorporates a message to be signed. For this proof, we leverage recent progress of Giacomelli et al. (USENIX'16) in constructing an efficient Σ-protocol for statements over general circuits. We improve this Σ-protocol to reduce proof sizes by a factor of two, at no additional computational cost. While this is of independent interest as it yields more compact proofs for any circuit, it also decreases our signature sizes. We consider two possibilities to make the proof non-interactive: the Fiat-Shamir transform and Unruh's transform (EUROCRYPT'12, '15,'16). The former has smaller signatures, while the latter has a security analysis in the quantum-accessible random oracle model. By customizing Unruh's transform to our application, the overhead is reduced to 1.6x when compared to the Fiat-Shamir transform, which does not have a rigorous post-quantum security analysis. We implement and benchmark both approaches and explore the possible choice of f, taking advantage of the recent trend to strive for practical symmetric ciphers with a particularly low number of multiplications and end up using Low MC (EUROCRYPT'15).

In recent years, more and more multimedia data are generated and transmitted in various fields. So, many encryption methods for multimedia content have been put forward to satisfy various applications. However, there are still some open issues. Each encryption method has its advantages and drawbacks. Our main goal is expected to provide a solution for multimedia encryption which satisfies the target application constraints and performs metrics of the encryption algorithm. The Advanced Encryption Standard (AES) is the most popular algorithm used in symmetric key cryptography. Furthermore, chaotic encryption is a new research direction of cryptography which is characterized by high initial-value sensitivity and good randomness. In this paper we propose a hybrid video cryptosystem which combines two encryption techniques. The proposed cryptosystem realizes the video encryption through the chaos and AES in CTR mode. Experimental results and security analysis demonstrate that this cryptosystem is highly efficient and a robust system for video encryption.

In 2013, researchers from the National Security Agency of the USA (NSA) proposed two lightweight block ciphers SIMON and SPECK [3]. While SIMON is tuned for optimal performance in hardware, SPECK is tuned for optimal performance in software. At CHES 2015, Yang et al. [6] combined the "good" design components from both SIMON and SPECK and proposed a new lightweight block cipher SIMECK that is even more compact and efficient. In this paper we show that SIMECK is vulnerable to fault attacks and demonstrate two fault attacks on SIMECK. The first is a random bit-flip fault attack which recovers the n-bit last round key of Simeck using on average about n/2 faults and the second is a more practical, random byte fault attack which recovers the n-bit last round key of SIMECK using on average about n/6.5 faults.

Radio-frequency identification (RFID) are becoming a part of our everyday life with a wide range of applications such as labeling products and supply chain management and etc. These smart and tiny devices have extremely constrained resources in terms of area, computational abilities, memory, and power. At the same time, security and privacy issues remain as an important problem, thus with the large deployment of low resource devices, increasing need to provide security and privacy among such devices, has arisen. Resource-efficient cryptographic incipient become basic for realizing both security and efficiency in constrained environments and embedded systems like RFID tags and sensor nodes. Among those primitives, lightweight block cipher plays a significant role as a building block for security systems. In 2014 Manoj Kumar et al proposed a new Lightweight block cipher named as FeW, which are suitable for extremely constrained environments and embedded systems. In this paper, we simulate and synthesize the FeW block cipher. Implementation results of the FeW cryptography algorithm on a FPGA are presented. The design target is efficiency of area and cost.