Issues In Cryptography Research Articles

CKAA: Certificateless key‐agreement authentication scheme in digital twin telemedicine environment

AbstractDigital twin (DT) technology provides accurate and real‐time visualization data. It is increasingly used in telemedicine to enhance medical efficiency and improve the precision of remote diagnosis and treatment. In telemedicine, DT is used to collect patients' biomedical data and transmit it to cloud servers through wearable devices for simulation, enabling remote diagnosis and treatment. However, telemedicine poses security threats due to the risk of medical data leaks. The security of medical data in transit and the authentication of communication entities are two key issues in cryptography. To address these issue, we propose a certificateless key agreement authentication scheme that does not rely on traditional public key infrastructure and certificate management, reducing the storage cost of resource‐limited wearable devices and avoiding the use of bilinear pairings to lower computational costs. Our scheme includes two parts of key agreement: one between the patient and the cloud server and the other between the patient and the hospital. Through these key agreements, we can ensure the privacy and integrity of medical data during transmission. Furthermore, we prove that the security of our scheme is equivalent to the elliptic curve discrete logarithm assumption in the random oracle model. Therefore, we provide a secure and efficient certificateless key agreement authentication solution that is suitable in digital twin telemedicine environments, particularly for client devices with limited functionality.

Multiple approaches to Convert RNS to Decimal Numbers

Improving the performance and speed of encryption algorithms is an important issue in cryptography. One of these improvements is the use of the RNS system. In the research, the RNS system and how to retrieve numbers from the RNS system to WNS weight number system or (decimal number) where discussed in several ways, and after performing multiplication operations, giving illustrative examples and making comparisons between methods.

Simulation of quantum key distribution in a secure star topology optimization in quantum channel

The field of quantum cryptography is mostly theoretical therefore in this paper we represent its implementation by means of virtual scenarios. The central issue in cryptography is the secure transmission of the key between nodes. Thus, in this paper we establish a secure channel using Quantum Key Distribution (QKD) for the transfer of the key material between the nodes and help to identify an eavesdropper in the channel. A graphical representation of the quantum channel traffic at the ideal state and also during network disruption has been established. Due to the complex nature of quantum networks and high cost of establishment, a physical implementation of the same is not feasible. Hence a simulation has been implemented via the use of NS-3 (Network Simulator Version 3) which has QKDNetSim module built into it. Finally, our simulation indicates the presence of an intruder by virtue of various network implementations within the quantum channel.

КРИПТОГРАФИЯ: ОТ ПРОШЛОГО К БУДУЩЕМУ

The article is devoted to the analysis of modern trends in the development of cryptography, which are related to the issues of cryptography of the past and are reflected in the prospects for the development of cryptography in the future. New trends in the development of cryptography that are relevant in recent decades are highlighted, the main ones of which include: awareness of the mathematical nature of data encryption problems, the rapid increase in the volume of processed and encrypted information that is distributed among a large unlimited circle of users of the modern data transmission devices, practical and theoretical interest of user s in cryptography. It analyzes the continuity of the issues facing cryptography. Among such issues there are: an importance of the human factor in the use of any cryptographic system, the traditional participation of the state in the cryptography development, as well as the theoretical substantiation of ideas of the cryptographic data protection, generalizing the practical experience of using encryption. The author also analyzes the main tasks of cryptography, which include identification, authentication, maintaining the integrity, confidentiality and availability of information during its transfer and storage, emphasizing the need to solve them within the framework of the design and implementation of the complex security systems. Using the development of quantum cryptography as an example, the article emphasizes that the development of new approaches to the cryptographic data protection traditionally leads to the emergence of new vulnerability factors, which means that the traditional issue of cryptography is also to stay ahead of potential attackers.

Construction of CCZ transform for quadratic APN functions

Almost perfect nonlinear (APN) function is an important type of function in cryptography, especially quadratic APN function. Since the notion of CCZ-equivalence developed, the construction of CCZ transform for APN functions to obtain new APN functions became a critical issue in cryptography. Inspired by the result of Budaghyan who used Gold functions, this article gives the construction of CCZ transform for all quadratic vectorial Boolean functions and proves that for quadratic APN functions, the functions transformed have algebraic degree 3, thus EA-inequivalent to all quadratic functions, and have minimum algebraic degree 2, thus EA-inequivalent to all power functions.

Self-updatable encryption: Time constrained access control with hidden attributes and better efficiency

Revocation and key evolving paradigms are central issues in cryptography, and in PKI in particular. A novel concern related to these areas was raised in the recent work of Sahai, Seyalioglu, and Waters (CRYPTO 2012) who noticed that revoking past keys should at times (e.g., the scenario of cloud storage) be accompanied by revocation of past ciphertexts (to prevent unread ciphertexts from being read by revoked users). They introduced revocable-storage attribute-based encryption (RS-ABE) as a good access control mechanism for cloud storage. RS-ABE protects against the revoked users not only the future data by supporting key-revocation but also the past data by supporting ciphertext-update, through which a ciphertext at time T can be updated to a new ciphertext at time T+1using only the public key. Motivated by this pioneering work, we ask whether it is possible to have a modular approach, which includes a primitive for time managed ciphertext update as a primitive. We call encryption which supports this primitive a “self-updatable encryption” (SUE). We then suggest a modular cryptosystems design methodology based on three sub-components: a primary encryption scheme, a key-revocation mechanism, and a time-evolution mechanism which controls the ciphertext self-updating via an SUE method, coordinated with the revocation (when needed). Our goal in this is to allow the self-updating ciphertext component to take part in the design of new and improved cryptosystems and protocols in a flexible fashion. Specifically, we achieve the following results:We first introduce a new cryptographic primitive called self-updatable encryption (SUE), realizing a time-evolution mechanism. In SUE, a ciphertext and a private key are associated with time. A user can decrypt a ciphertext if its time is earlier than that of his private key. Additionally, anyone (e.g., a cloud server) can update the ciphertext to a ciphertext with a newer time. We also construct an SUE scheme and prove its full security under static assumptions. Following our modular approach, we present a new RS-ABE scheme with shorter ciphertexts than that of Sahai et al. and prove its security. The length efficiency is mainly due to our SUE scheme and the underlying modularity. We apply our approach to predicate encryption (PE) supporting attribute-hiding property, and obtain a revocable-storage PE (RS-PE) scheme that is selectively-secure. We further demonstrate that SUE is of independent interest, by showing it can be used for timed-release encryption (and its applications), and for augmenting key-insulated encryption with forward-secure storage.

CRYPTOPOLEMIADE

This paper is polemical in character and considers some issues in cryptography (symmetric block ciphers) from a perspective other than a conventional one. The author has attempted to apply Altschuller's methods to cryptography (recently, it has become overburdened with mathematics and become an authoritarian science) and apologizes to professionals with a fundamental education in cryptology for using an engineer's lingo.

INTEGRATION OF CFEA-COMPRESSION TECHNIQUE INTO ASYMMETRIC KEY CRYPTOSYSTEMS

In order to provide good level of security, modern cryptosystems need to implement large numbers and complicated mathematical operations. As a consequence, efficiency becomes a new major issue in cryptography. By using proper parameters, some of established asymmetric cryptosystems are believed to be able to provide a good level of security. Since that, aim to develop a mechanism to accelerate encryption and decryption processes of asymmetric cryptosystem without altering their original encryption and decryption algorithms become a big consideration. The aim of this paper is to propose the integration of a compression technique that named as CFEA-Compression technique into some established asymmetric key cryptosystem such as RSA, El-Gamal and Elliptic Curve cryptosystems. CFEA-technique is a combination of Continued Fraction and Euclidean Algorithm (CFEA) which is able to reduce the number of plaintext and ciphertext prior the encryption and decryption procedures.

BCES Encryption Algorithm

A fundamental problem in cryptography is how to communicate securely over an insecure channel. This problem has been there for a long time and has become even more important especially with the proliferation of computers and communication systems. Achieving information and communications security in an electronic society requires a vast array of technical and algorithms, without which the information security objectives deemed necessary cannot be adequately met. For this reason, this paper aims to propose a new algorithm to improve the security level. That is called as BCES algorithm. Thus, the rest of this paper is organized to offer an overview of basic issues of cryptography and describes in detail a new algorithm. Keywords: BCES, encryption, public key, decryption, algorithm, ASCII

On the security of $\alpha\eta$: response to 'some attacks on quantum-based cryptographic protocols'

Lo and Ko have developed some attacks on the cryptosystem called $\alpha \eta$}, claiming that these attacks undermine the security of $\alpha\eta$ for both direct encryption and key generation. In this paper, we show that their arguments fail in many different ways. In particular, the first attack in [1] requires channel loss or length of known-plaintext that is exponential in the key length and is unrealistic even for moderate key lengths. The second attack is a Grover search attack based on `asymptotic orthogonality' and was not analyzed quantitatively in [1]. We explain why it is not logically possible to "pull back'' an argument valid only at $n=\infty$ into a limit statement, let alone one valid for a finite number of transmissions n. We illustrate this by a `proof' using a similar asymptotic orthogonality argument that coherent-state BB84 is insecure for any value of loss. Even if a limit statement is true, this attack is a priori irrelevant as it requires an indefinitely large amount of known-plaintext, resources and processing. We also explain why the attacks in [1] on $\alpha\eta$ as a key-generation system are based on misinterpretations of [2]. Some misunderstandings in [1] regarding certain issues in cryptography and optical communications are also pointed out. Short of providing a security proof for $\alpha\eta$, we provide a description of relevant results in standard cryptography and in the design of $\alpha\eta$ to put the above issues in the proper framework and to elucidate some security features of this new approach to quantum cryptography.

The campaign for an ethical Internet

The fostering of an Internet societal infrastucture which is consciously ethical, is needed to curtail the new era of global irresponsibility that is at hand. The positive view advanced is contrasted with a scenario of the silencing of a moral Internet community using regulatory constraints, an extension of broadcast techniques, "brain-free" hardware, and control by multi-national corporations. This positive scenario is dependent on the evolution of a moral and responsible Internet global citizenry. The global citizen will recognise that in creating an era of peace and negotiation, the traditional boundaries of nation or of cultural difference may be radically redefined, but not destroyed. Two central problems, that of establishing an acceptable moral basis for global citizenship, and that of enabling the integrity of cultural and ethnic groups to be maintained in a global electronic environment, are discussed. A primary task for the Internet community is to establish a Code of Ethics. This could be based on the following principles: a strong and coherent Internet infrastructure; maintenance of interconnectivity; open Internet commerce; privacy of communications; freedom of speech within the Internet (with the proviso that the best interests of children are protected in information delivery); universal Internet access; freely accessible "public good" information; mediation between national and global organizations in the interests of the Internet; authentication of information (or establishment of levels of verification of information sources); and maintenance of adequate bandwidth. These principles encompass some of the fiercest debates of the Internet regulatory environment, including those on issues of cryptography, copyright, software patents, first-level domain names, and pornography.