Security Primitives: Block And Stream Ciphers

2008

This paper looks at the possibility of combining a block cipher and a stream cipher to get a strong hybrid cipher. It includes two specific proposals for combining AES-128 and RC4-128 to get a cipher that takes a 256-bit key and is significantly faster than AES-256, and arguably more secure. One is immune to algebraic attacks.

International Journal of Applied Physics and Mathematics, 2015

By employing the characteristics of the basic structure (keystream), Stream ciphers designers attempt to create algorithms that have advanced features from security and speed point of view. They take into consideration the state-of-the-art scientific and technical developments to design more advanced algorithm versions. This research proposes the design of a new efficient and secure stream cipher, named BloStream which proves to be more secure than conventional stream ciphers that commonly implement Exclusive-OR (XOR) for mixing. The proposed algorithm encompasses two major components. The first part involves the Pseudo Random Number Generator (PRNG), exhausting Rabbit algorithm. And the second part involves a nonlinear invertible round function (combiner), depending on Rijndael-like function algorithm, to perform the encryption/decryption processes. This new construction strengthens the weak XOR combiner. The proposed cipher is not only a random number generator but also a self-synchronizing stream cipher in such a way that the cipher text influences its internal functioning. The proposed algorithm utilizes 16-bytes secret key to encrypt the plaintext which is a multiple of 16-bytes up to 2 64 bytes length. The evaluation of BloStream performance, in terms of implementation aspects and security properties as well as the statistical test for keystream and comparison with similar systems revealed that, BloStream was more efficient, faster, and securer than the conventional stream ciphers.

The number of internet of things (IoT) applications has increased, which has increased the demand for low-resource gadgets. The data produced by these devices must be protected to guarantee security. The devices operate in conditions with limited space, computational power, memory, and energy. High-security standards are difficult to achieve with limited resources. The detailed analysis of various stream ciphers and their performance metrics is reviewed in this manuscript. The functionality of the stream ciphers is categorized and thoroughly discussed based on both the hardware and software viewpoints. The security attacks and their countermeasure methods using stream ciphers are discussed. The performance metrics of most hardware-based stream ciphers, including the ECRYPT stream cipher project (eSTREAM) ciphers, are discussed. Each hardware stream cipher design highlights the hardware constraints such as chip area, frequency, throughput, and hardware efficiency. The work also highlights the various applications using these stream ciphers. The current trends using these stream ciphers are discussed with futuristic goals.

Lecture Notes in Computer Science, 1998

This paper examines proposals for three cryptographic primitives: block ciphers, stream ciphers, and hash functions. It provides an overview of the design principles of a large number of recent proposals, which includes the global structure, the number of rounds, the way of introducing non-linearity and diffusion, and the key schedule. The software performance of about twenty primitives is compared based on highly optimized implementations for the Pentium. The goal of the paper is to provided a technical perspective on the wide variety of primitives that exist today.

IETE Journal of Education, 2020

This paper reviews the state of the art of symmetric key block cipher designs and their essential security role in several applications like IoT, low-power devices like motes, etc. Many engineering curricula have one course on network and internetwork security at the undergraduate level. However due to the expanding research on newer and newer primitives and host of published literature in the area of protocols, algorithms for encryption, authentication, message integrity, key exchange, it is of interest to deliver (teach) as much information as possible within one or two semester courses in the undergraduate engineering curriculum. In this paper, our objective is to present a comprehensive review of design approaches including Feistel, SPN, ARX, and other hybrid structures and also highlight various cryptanalysis techniques and attacks. We focus on what topics that need to be covered and to what depth in this paper. Further, this paper also presents the performance metrics that are commonly reported in the literature when comparing block cipher implementations. These are necessary since the students should finally be able to appreciate how to benchmark and know what industry needs.

DAIMI Report Series, 1994

In this thesis we study cryptanalysis, applications and design of secret key block ciphers. In particular, the important class of <em> Feistel ciphers</em> is studied, which has a number of rounds, where in each round one applies a cryptographically weak function.

2020

Today cryptographic methods use to provide confidentiality and integrity of the data. In other hand, there are many threats related to security breaches and restricted access data leakage in up-to-date information and communication technologies (ICT). The most popular and effective attacks are linear and differential cryptanalysis (LDC) as well as quantitative security assessment characterizing practical security against LDC is actual research task. Another valuable parameter is cryptographic data processing speed; as a rule it is decreasing in algorithms with high processing complexity. As time goes on some algorithms become worn out and outdated (i.e. DES, GOST 28147-89) as well as new more secure and high-speed algorithms are used in modern ICT (webapplications, IoT, blockchain, critical infrastructure). From this position, in this paper method of cryptographic security algorithms constructing for critical applications has been improved. This method uses substitution tables with ...

Telecommunication Systems, 2010

In this paper we introduce a general framework of related-key attack on block-wise stream ciphers which are suitable for the protection of multimedia and ubiquitous systems. As a case study, we show how our cryptanalytic framework is applied to a block-wise stream cipher TWOPRIME: we construct various related-key differentials of TWOPRIME and use them to show that recovering related keys of TWOPRIME can be performed with a data complexity of 2 14 known plaintext blocks and a time complexity of 2 32 8-bit table lookups. We expect that our general framework for a related-key attack would be useful tool for analyzing many of block-wise stream ciphers.

ArXiv, 2012

This paper proposes a new block cipher termed as “Modular Arithmetic based Block Cipher with Varying Key-Spaces (MABCVK)” that uses private key-spaces of varying lengths to encrypt data files. There is a simple but intelligent use of theory of modular arithmetic in the scheme of the cipher. Based on observed implementation of the proposed cipher on a set of real data files of several types, all results are tabulated and analyzed. The schematic strength of the cipher and the freedom of using a long key-space expectedly can make it reasonably nonvulnerable against possible cryptanalytic attacks. As a part of the future scope of the work, it is also intended to formulate and implement an enhanced scheme that will use a carrier image to have a secure transmission of the private key

The new attack methods show some lacuna in the encryption algorithms and key schedule. As the strength of an encryption algorithm depends on the difficulty of cracking the original message, a number of symmetric key encryption algorithms like DES, TRIPLE DES, AES, BLOWFISH, and RC6 have been developed to provide greater security affects. Most of them are most popular in achieving data security at a great extent like AES. But, as security level is increased, the time and complexity of algorithm is also increased. This is the major cause of decreasing speed and efficiency of the encryption system. This paper presents a new algorithm for block data encryption that enhances the security level. The proposed algorithm is executed with block wise parallel encryption model to decrease the delay time.