Within quantum networks (employing quantum key distribution - QKD), the attacker has no chance to get hold of the established keys (most commonly used as one time pads) without being detected by the communicating parties. So the attacker might change his strategy to denial of service in order to inhibit the efficient usage of the quantum-key-distribution-links and one-time-pad-encryption and hence to force the use of classical (a)symmetric cryptography. In this paper we will propose a method for strengthening classical cryptographic algorithms by the use of small amounts of one time pads, so that these algorithms can be used for an emergency operation when suffering a Denial-of-Service attack and during the time needed to fix it. Additional scenarios of using the presented approach include the down time of QKD-links or QKD-devices in case of failure or maintenance.
Within quantum networks (employing quantum key distribution - QKD), the attacker has no chance to get hold of the established keys (most commonly used as one time pads) without being detected by the communicating parties. So the attacker might change his strategy to denial of service in order to inhibit the efficient usage of the quantum-key-distribution-links and one-time-pad-encryption and hence to force the use of classical (a)symmetric cryptography. In this paper we will propose a method for strengthening classical cryptographic algorithms by the use of small amounts of one time pads, so that these algorithms can be used for an emergency operation when suffering a Denial-of-Service attack and during the time needed to fix it. Additional scenarios of using the presented approach include the down time of QKD-links or QKD-devices in case of failure or maintenance.
Currently many symmetric key cryptographic tools which are known to be quantum-safe. They all share Secret symmetric keys through an untrusted medium which is usually done with public key methods which are prone to quantum attacks. One among the recommended solutions to the key distribution problem is Quantum Key Distribution (QKD). QKD utilizes an authenticated Communication channel along with a quantum communication channel so that a secret key is generated. Whatever may be the protocol to implement proposed QKD, they all need both a quantum channel, and an authenticated classical. OTP (One Time Pad) is used when two parties wish to communications have to share a key called pad. This pad is a randomly generated key and the length of the key should be equal to the message so it can be sent. The proposed QKD parameters that result in almost 35.67% smaller keys for quantum security and an implementation of QKD in network which is publicly available and usable in practice.
Quantum cryptography Ð quantum key distribution (QKD) Ð was one of the first fields of study of quantum information theory.It reached a mature scientific level and has been implemented in commercial systems for secure quantum communications.The key distribution problem is the central issue of symmetric cryptography.Quantum cryptography solves this problem on the basis of the fundamental laws of nature: the principles of quantum mechanics.Quantum key distribution is essentially matching two independent random sequences on the transmitting and receiving sides by exchanging quantum states.Required in addition to the quantum channel is an authentic classical communication channel.Both communication channels are open and vulnerable to a perpetrator's attack.To ensure the authenticity of the classical channel at initial system startup, a seed key is required, which is used to provide information-theoretic authentication.In essence, quantum cryptography systems are mechanisms for expanding this seed key.Subsequent sessions generate a quantum key, part of which is used for authentication, while another part is employed for other cryptographic purposes, such as encryption.An issue fundamental for quantum cryptography is the number of quantum key distribution sessions that can be conducted from the initial system launch until a new system reboot, when the cryptographic properties of the quantum keys reach a critical level, after which they can no longer be used for cryptographic purposes, and a new system reboot is needed.Although a number of reviews on quantum cryptography are currently available, this issue has not been discussed in detail.It is shown that for realistic parameters of quantum cryptography systems that are currently achievable, a QKD system can operate for I.
As we move further into the era of digital transformation, cloud services are becoming a cornerstone across industries such as healthcare, agriculture, and Industry 4.0. These sectors increasingly rely on cloud environments to collect, process, and store vast amounts of data, often integrated with smart devices. While ensuring high availability and efficiency remains vital, the paramount concern is maintaining data security. This challenge becomes even more pressing in a world where quantum computers pose a serious threat to traditional cryptographic methods. Classical encryption schemes, particularly those relying on computational hardness assumptions, are susceptible to quantum attacks. This paper proposes a solution by combining the theoretically unbreakable One-Time Pad (OTP) encryption with quantum-safe key exchange protocols. Through the integration of Quantum Key Distribution (QKD) and post-quantum cryptographic techniques, we outline a robust framework designed to secure communication in the coming quantum era.
Cryptography plays an integral role in secure communication and is usually the strongest link in the chain of security. Yet security problems abound in electronic communication: spyware, phishing, denial of service, and side-channel attacks are still major concerns. The main goal in this thesis is to consider how cryptographic techniques can be extended to offer greater defence against these non-traditional security threats. \n \nIn the first part of this thesis, we consider problems in classical cryptography. We introduce multi-factor password-authenticated key exchange which allows secure authentication and key agreement based on multiple short secrets, such as a long-term password and a one-time response; it can provide an enhanced level of assurance in higher security scenarios because a multi-factor protocol is designed to remain secure even if all but one of the factors has been compromised due to attacks such as phishing or spyware. Next, we consider the integration of denial of service countermeasures with key exchange protocols: by introducing a formal model for denial of service resilience that complements the extended Canetti-Krawczyk model for secure key agreement, we cover a wide range of existing denial of service attacks and prevent them by carefully using client puzzles. Additionally, we look at how side-channel attacks affect certain types of formulae used in elliptic curve cryptography, and demonstrate that information leaked during field operations such as addition, subtraction, and multiplication can be exploited by an attacker. \n \nIn the second part of this thesis, we examine cryptography in the quantum setting. We argue that quantum key distribution will have an important role to play in future information security infrastructures and will operate best when integrated with the powerful public key infrastructures that are used today. Finally, we present a new look at quantum money and describe a quantum coin scheme where the coins are not easily counterfeited, are locally verifiable, and can be transferred to another party.
Quantum computing is an interdisciplinary field comprising of physics, mathematics and computer science that leverages quantum mechanics to complete complicated tasks more quickly than classical computers.It includes both the advancement of hardware research and application development.In the paper on quantum computing, quantum cryptography/Quantum Key Distribution, the revolutionary paradigm shift in computation is introduced, exploring the enigmatic world where quantum bits, or qubits, replace classical bits.Computational efficiency is increased through the manipulation of probabilities made easier by quantum interference.Furthermore, we examined the applications of quantum cryptography, which makes use of the ideas of quantum physics to guarantee secure communication.As a cornerstone, quantum key distribution appears, providing cryptographic keys encoded in quantum states with unbreakable encryption.The proposed work serves as a gateway to understand the profound implications and limitless potential of quantum computing and cryptography.The main contribution of the proposed work is to enhance the performance of the Quantum One-Time Pad (QOTP) algorithm in order to reduce the amount of classical key information needed while preserving the same level of security.The proposed approach combines entanglement with the QOTP, allowing secure communication without needing new key bits for each qubit encrypted.
A QKD network can be considered an add-on technology to a standard communication network that provides IT-secure cryptographic keys as a service. As a result, security challenges resulting in the suspension of functional work must be addressed. This study analyzes a Denial of Service (DoS) attack on the Key Management System (KMS), one of the critical components of the QKD network in charge of key management and key provisioning to authorized consumers. Through simulation methods performed in the QKDNetSim, we show that legitimate customers experience significantly worse service during an excessive DoS attack on KMS.