This paper introduces the first two-dimensional XOR-based secret sharing scheme for layered multipath communication networks. We present a construction that guarantees successful message recovery and perfect privacy when an adversary observes and disrupts any single path at each transmission layer. The scheme achieves information-theoretic security using only bitwise XOR operations with linear O(|S|) complexity, where |S| is the message length. We provide mathematical proofs demonstrating that the scheme maintains unconditional security regardless of computational resources available to adversaries. Unlike encryption-based approaches vulnerable to quantum computing advances, our construction offers provable security suitable for resource-constrained military environments where computational assumptions may fail.
This paper introduces the first two-dimensional XOR-based secret sharing scheme for layered multipath communication networks. We present a construction that guarantees successful message recovery and perfect privacy when an adversary observes and disrupts any single path at each transmission layer. The scheme achieves information-theoretic security using only bitwise XOR operations with linear O(|S|) complexity, where |S| is the message length. We provide mathematical proofs demonstrating that the scheme maintains unconditional security regardless of computational resources available to adversaries. Unlike encryption-based approaches vulnerable to quantum computing advances, our construction offers provable security suitable for resource-constrained military environments where computational assumptions may fail.
Sending private messages over communication environments under surveillance is an important challenge in communication security and has attracted attentions of cryptographers through time. We believe that resources other than cryptographic keys can be used for communication privacy. We consider private message transmission (PMT) in an abstract multipath communication model between two communicants, Alice and Bob, in the presence of an eavesdropper, Eve. Alice and Bob have pre-shared keys and Eve is computationally unbounded. There are a total of n paths and the three parties can have simultaneous access to at most ta, tb, and te paths. The parties can switch their paths after every λ bits of communication. We study perfect (P)-PMT versus asymptotically-perfect (AP)-PMT protocols. The former has zero tolerance of transmission error and leakage, whereas the latter allows for positive error and leakage that tend to zero as the message length increases. We derive the necessary and sufficient conditions under which P-PMT and AP-PMT are possible. We also introduce explicit P-PMT and AP-PMT constructions. Our results show AP-PMT protocols attain much higher information rates than P-PMT ones. Interestingly, AP-PMT is possible even in poorest condition where ta=tb=1 and te=n−1. It remains however an open question whether the derived rates can be improved by more sophisticated AP-PMT protocols. We study applications of our results to private communication over the real-life scenarios of multiple-frequency links and multiple-route networks. We show practical examples of such scenarios that can be abstracted by the multipath setting: Our results prove the possibility of keyless information-theoretic private message transmission at rates 17% and 20% for the two example scenarios, respectively. We discuss open problems and future work at the end.
This paper explores the foundational principles and practical implications of achieving information-theoretic security through quantum entanglement. Information-theoretic security, independent of computational complexity assumptions, offers unparalleled privacy and integrity. Classical cryptography relies on unproven mathematical hardness, making it vulnerable to future quantum computers. Quantum mechanics, specifically entanglement, provides a novel paradigm for cryptographic protocols with unconditional security, guaranteed by the laws of physics. We detail how entanglement enables certain eavesdropping detection and generates truly random shared secret keys. The discussion encompasses key protocols, the role of Bell inequalities, and theoretical security proofs underpinning these quantum systems. We also address current challenges and future prospects for deploying entanglement-based secure communication networks, highlighting its transformative potential for a future-proof global communication infrastructure. This work synthesizes how quantum entanglement shifts cryptographic assurance from computational assumptions to fundamental physical laws, setting the stage for truly uncompromisable communication. We further acknowledge the ethical considerations and societal implications of such robust encryption.
In the model of Perfectly Secure Message Transmission Schemes (PSMTs), there are n channels between a sender and a receiver, and they share no key. An infinitely powerful adversary A can corrupt (observe and forge) the messages sent through some subset of n channels. For non-threshold adversaries called Q 2, Kumar et al. showed a many round PSMT (Ashwin Kumar et al. On perfectly secure communication over arbitrary networks. PODC 2002, pp. 193---202, 2002). In this paper, we show round efficient PSMTs against Q 2-adevrsaries. We first give a 3-round PSMT which runs in polynomial time in the size of the underlying linear secret sharing scheme. We next present a 2-round PSMT which is inefficient in general. (However, it is efficient for some special case.)
In the model that has become known as “Perfectly Secure Message Transmission” (PSMT), a sender Alice is connected to a receiver Bob through n parallel two-way channels. A computationally unbounded adversary Eve controls t of these channels, meaning she can acquire and alter any data that is transmitted over these channels. The sender Alice wishes to communicate a secret message to Bob privately and reliably, i.e. in such a way that Eve gains no information about the message while Bob is able to recover it completely. We focus on PSMT protocols that work in two transmission rounds for n = 2t + 1. We break from previous work by following a conceptually simpler blueprint. This has two consequences: first, we obtain improved efficiency, namely, we reduce the previously best-known communication complexity, i.e. the number of transmitted bits necessary to communicate a 1-bit secret, from O(n3log n) to O(n2log n). Our solution also reaches optimal transmission rate for a secret of size O(n log n), thus answering the hitherto open question of attaining a threshold below O(n2log n) bits. Second, our construction can be adapted to more general scenarios relevant to Network Coding, where the adversary is given more power.
Abstract In this paper, we consider an interesting and important privacy-preserving issue, i.e., how to implement anonymous and secure communications for several intelligence agents, hiding in n participants. To solve this issue, we first propose a quantum Secure Multiparty Computing XOR (SMC_XOR) protocol based on single photons, which can guarantee the unconditional security of the protocol. By implementing rotation encryption, the practicality of quantum SMC_XOR protocol can be significantly improved without other complex quantum techniques. Security analysis shows that the proposed protocol can resist various types of attacks. Furthermore, a special network model is designed to solve this issue, using hash function to verify the identity of the communication parties and key recycling to reduce resource consumption. Finally, the proposed quantum SMC_XOR protocol is simulated in IBM Qiskit, and the simulation results show that the protocol is correct and feasible.
Shannon showed that to achieve perfect secrecy in point-to-point communication, the message rate cannot exceed the shared secret key rate giving rise to the simple one-time pad encryption scheme. In this paper, we extend this work from point-to-point to networks. We consider a connected network with pairwise communication between the nodes. We assume that each node is provided with a certain amount of secret bits before communication commences. An eavesdropper with unlimited computing power has access to all communication and can hack a subset of the nodes not known to the rest of the nodes. We investigate the limits on information-theoretic secure communication for this network. We establish a tradeoff between the secure channel rate (for a node pair) and the secure network rate (sum over all node pair rates) and show that perfect secrecy can be achieved if and only if the sum rate of any subset of unhacked channels does not exceed the shared unhacked-secret-bit rate of these channels. We also propose two practical and efficient schemes that achieve a good balance of network and channel rates with perfect secrecy guarantee. This work has a wide range of potential applications for which perfect secrecy is desired, such as cyber-physical systems, distributed-control systems, and ad-hoc networks.