Abstract Sudoku grids are often cited as being useful in cryptography as a key for some encryption process. Historically transporting keys over an alternate channel has been very difficult. This article describes how a Sudoku grid key can be secretly transported using quantum key distribution methods whereby partial grid (or puzzle) can be received and the full key can be recreated by solving the puzzle.
Abstract Sudoku grids are often cited as being useful in cryptography as a key for some encryption process. Historically transporting keys over an alternate channel has been very difficult. This article describes how a Sudoku grid key can be secretly transported using quantum key distribution methods whereby partial grid (or puzzle) can be received and the full key can be recreated by solving the puzzle.
Classical cryptographic systems are increasingly challenged by advances in computing power and new algorithmic techniques, particularly with the rise of quantum computing, which threatens the security of current encryption methods. This has spurred interest in quantum-resistant cryptography, aimed at creating algorithms that can withstand attacks from quantum computers. Traditionally, secure key transport over alternate channels has been a significant challenge, but quantum mechanics offers a solution. Quantum Key Distribution (QKD) is a revolutionary method for secure communication that leverages quantum principles. Unlike traditional methods, QKD provides unconditional security, with key security ensured by the laws of physics rather than computational difficulty. The BB84 protocol, introduced in 1984 by Bennett and Brassard, is a leading QKD scheme known for its simplicity and effectiveness in generating eavesdropping-resistant cryptographic keys. It facilitates secure key transport over alternate channels. This documentation aims to advance QKD security by practically implementing and analyzing the BB84 protocol. Through detailed theoretical analysis, simulation studies, and experimental validation, the practical impacts, and limitations of BB84-based QKD systems are examined. Additionally, a practical implementation of quantum key distribution using a sudoku key demonstrates the process's simplicity and effectiveness. These findings are expected to pave new paths in the field of cryptanalysis in the emerging Quantum Age.
Smart grid depends on an advanced communication network to collect information from the power grid, and to disseminate control commands to the control devices. To safeguard the power grid, it is crucial to ensure information confidentiality in the communication networks. Quantum key distribution (QKD) protocols help in generating, and distributing secret keys between communication parties, and such secret keys are required in symmetric cryptography. The combination of QKD protocols, and symmetric cryptography are known to be unconditionally secure, which means information confidentiality can be guaranteed even against an eavesdropper, who has unlimited resources. This article provides a concise review of existing works on QKD protocols, and their applications in smart grid communications. Deploying QKD protocols in smart grid is challenging because distance between the control center, and control devices can be larger than the limits of existing protocols. Also, QKD protocols require an expensive quantum channel between each pair of sender, and receiver nodes, and there is large number of control devices with diverse capabilities in smart grid. We have classified existing works based on the challenges they have dealt with. Compared to the rich literature on QKD protocols in general, there are significantly fewer works in the specific context of smart grid. This can be an indication for opportunity to make a significant contribution. We have also identified a few research challenges that can be potential future works.
Abstract Cryptography is a scientific method that is used to transmit secret information. In contrast, quantum cryptography depends on physical laws to encrypt information; when the quantum computer appeared, the classic encryption method becomes inefficient. The quantum method is commonly used to distribute keys, a process called as quantum key distribution (QKD). In this paper, we consider the efficiency of the quantum method compared to classical methods. Also, we discuss the security of QKD against several attacks and provide security analysis based on probabilistic models. Additionally, the paper explains how to encrypt random numbers into a sequence of photons using a QKD system for the distribution of a key. This research demonstrates the efficiency and security of QKD in sending and distributing keys between communication parties. Thus, both the sender and the receiver would be able to obtain a security key using the quantum method rather than classical methods.
Quantum key distribution is a sub topic under quantum cryptography where two parties distribute a shared random bit string known only to them and which can be used as a key to encrypt and decrypt messages. This paper proposes a novel method of QKD to distribute the secret key. The basic concept of QKD remains the same but the process by which the key is exchanged between the two parties is different and is much more secure than the existing QKD protocols. The proposed method exploits the concept of hamming weight.
Most cryptographic mechanisms such as symmetric and asymmetric cryptography, often involve the use of cryptographic keys. However, all cryptographic techniques will be ineffective if the key distribution mechanism is weak. Quantum Key Distribution or Quantum Cryptography is attracting much attention as a solution of the problem of Key Distribution; QKD offers unconditionally secure communication based on quantum mechanics. This work presents quantum key distribution protocols (QKDP) to safeguard security in large networks, ushering in new directions in classical cryptography and quantum cryptography.
This article describes how to solve Sudoku puzzles using Quadratic Unconstrained Binary Optimization (QUBO). To this end, a QUBO instance with 729 variables is constructed, encoding a Sudoku grid with all constraints in place, which is then partially assigned to account for clues. The resulting instance can be solved with a Quantum Annealer, or any other strategy, to obtain the fully filled-out Sudoku grid. Moreover, as all valid solutions have the same energy, the QUBO instance can be used to sample uniformly from the space of valid Sudoku grids. We demonstrate the described method using both a heuristic solver and a Quantum Annealer.