Authenticated teleportation aims to certify the transmission of a quantum state through teleportation, even in the presence of an adversary. This scenario can be pictured in terms of an untrusted source distributing a Bell state between two parties who wish to verify it using some simple tests. We propose a protocol that achieves this goal in a practical way and analyze its performance and security when the parties have noisy measurement devices. Further, we model a realistic experimental scenario where the state is subject to noise. We finally apply our analysis to the verification of graph states with noisy measurement devices.
Authenticated teleportation aims to certify the transmission of a quantum state through teleportation, even in the presence of an adversary. This scenario can be pictured in terms of an untrusted source distributing a Bell state between two parties who wish to verify it using some simple tests. We propose a protocol that achieves this goal in a practical way and analyze its performance and security when the parties have noisy measurement devices. Further, we model a realistic experimental scenario where the state is subject to noise. We finally apply our analysis to the verification of graph states with noisy measurement devices.
The phenomenal progress in quantum technologies over the past decades has laid the groundwork for the construction of quantum networks, which will channel the power of quantum theory to guarantee secure and efficient communication, computation, and much more. This thesis studies the notion of trust in quantum networks. In our information age, protecting the security or anonymity of data is a key requirement. We investigate certain protocols that are fundamental to the operation and applications of quantum networks, and propose ways to test and analyse their security, in spite of adversarial intervention. Our focus is on practical methods of verifying the untrusted components, which could be incorporated into realistic networks in the near future. To begin, we propose a protocol for authenticated communication of quantum messages, by verifying the entanglement required for quantum teleportation in an experimentally feasible way. We model the performance of our scheme in the presence of noise. Furthermore, we explore such an authenticated teleportation in the one-sided device-independent scenario, where some devices used for verification may be corrupted. We derive error-tolerant self- testing bounds and extend our results to a realistic experimental setting, demonstrating the compatibility of our protocol with state-of-the-art technology. We then study anonymity, an essential feature for communication across networks. Combining the power of classical and quantum subroutines, we build a practical protocol for anonymous communication of quantum messages, without the need to trust the players in our network, their computational power, or the entanglement they share. We end by considering the verification of graph states distributed across a network of possibly dishonest players, applying our scheme to specific graph states that are central to quantum communication and computation schemes.
This work presents a simulation-based study of quantum teleportation for secure communication under ideal, noisy, and adversarial conditions using IBM’s Qiskit framework and the Qiskit Aer simulator. The study begins with the verification of Bell-state entanglement to establish quantum correlation, followed by the implementation of a standard three-qubit quantum teleportation protocol. The teleportation system is evaluated across four experimental scenarios: (i) ideal noiseless teleportation, (ii) depolarizing noise environments, (iii) basis disturbance attacks using unauthorized Hadamard operations, and (iv) entanglement injection attacks introducing an external qubit into the communication channel. Each scenario is analyzed using measurement statistics, probability distributions, and state behavior of the receiver qubit. The results demonstrate that quantum teleportation achieves high fidelity under ideal conditions, while environmental noise introduces statistical degradation in state reconstruction. Furthermore, adversarial interference significantly disrupts teleportation performance, with basis disturbance producing near-uniform probability distributions and entanglement injection altering receiver-side measurement statistics. This study highlights both the robustness and vulnerability of quantum communication protocols and emphasizes the importance of noise mitigation, entanglement security, and attack detection mechanisms in future quantum networking systems. The work is entirely simulation-based and implemented using Python and Qiskit.
Hiding the identity of involved participants in the network, known as anonymity, is a crucial issue in some cryptographic applications such as electronic voting systems, auctions, digital signatures, and Byzantine agreements. This paper proposes a new anonymous quantum teleportation protocol based on counterfactual communication where no information-carrying particles pass through the channel. It is achieved by the distribution of a counterfactual entanglement among the participants in the network followed by the establishment of an anonymous entanglement between the sender and the receiver. Afterwards, the sender can anonymously teleport a quantum state to the receiver by utilizing the anonymous entanglement. However, the practicality of the anonymous quantum network mainly calls for two performance measures-robustness against adversarial attacks and noisy environments. Motivated by these demands, firstly, we prove the security of our proposed protocol and show that it achieves both the sender and receiver's anonymity in the presence of active adversaries and untrusted parties. Along with anonymity, we also ensure the correctness of the protocol and the privacy of the teleported qubit. Finally, we analyze the robustness of our proposed protocol under the presence of channel noise and compare its fidelity with those of the conventional protocols. The main advantage of our proposed protocol is that it can provide useful anonymous quantum resources for teleportation under noisy environment with a higher security compared to previous protocols.
We introduce a protocol for authenticated teleportation, which can be proven secure even when the receiver does not trust his or her measurement devices, and which is experimentally accessible. We use the technique of self-testing from the device-independent approach to quantum information, where we can characterize quantum states and measurements from the exhibited classical correlations alone. First, we derive self-testing bounds for the Bell state and Pauli ${\ensuremath{\sigma}}_{X},{\ensuremath{\sigma}}_{Z}$ measurements, that are robust enough to be implemented in the laboratory. Then, we use these to determine a lower bound on the fidelity of an untested entangled state to be used for teleportation. Finally, we apply our results to propose a protocol for one-sided device-independent authenticated teleportation that is experimentally feasible in both the number of copies and fidelities required. This can be interpreted as a practical authentication of a quantum channel, with additional one-sided device independence.
Quantum teleportation, a cornerstone of quantum information science, enables the transfer of an unknown quantum state from one location to another without physically moving the particle itself. Its fidelity is paramount for practical applications in quantum computing and secure communication. A fundamental principle underpinning quantum mechanics is the no-cloning theorem, which prohibits the creation of an identical copy of an arbitrary unknown quantum state. This paper proposes and theoretically investigates a novel protocol for enhancing the fidelity of quantum teleportation by incorporating Bell-certified unclonability. By leveraging the strong correlations inherent in maximally entangled Bell states, our scheme introduces a mechanism to verify that the quantum state being teleported has not been illicitly copied prior to or during the teleportation process. This certification is achieved through local measurements and Bell tests, which confirm the integrity of the entangled channel and, by extension, the unclonability of the transmitted state. We analyze the theoretical underpinnings of this Bell-certification, its impact on the average fidelity of teleported states, and its robustness against various noise models. Our findings demonstrate that integrating unclonability certification through Bell tests significantly bolsters the security and reliability of quantum teleportation, offering a pathway towards truly high-fidelity and secure quantum information transfer in realistic noisy environments.
Position information underpins many modern technologies, from navigation and timing to authentication and critical infrastructure. However, classical methods of proving that information originates from a particular position are vulnerable to spoofing. This limitation can be overcome with quantum technologies but current protocols rely on trust in quantum hardware that can be undermined, or require quantum computers and bounds on adversarial computation. Nevertheless, there has been significant interest in experimental demonstrations, and aspects of these protocols have been implemented. Here we introduce and experimentally demonstrate the Bell-test quantum position verification protocol for device-independent quantum position verification that guarantees security with only observed correlations from a loophole-free Bell test across a quantum network. We experimentally implement a version of this device-independent protocol against adversaries who, before each trial, are weakly entangled. Our demonstration achieves a one-dimensional localization 2.47(2) times smaller than the best, necessarily non-remote, classical localization protocol. Compared to classical protocols with identical latencies, the localization volume is 4.53(5) times smaller, and represents a certifiable quantum advantage. The general Bell-test protocol is loss tolerant and secure against adversaries with significant quantum resources. This work allows digital security to be anchored to physically trusted locations, enabling new position-based authentication protocols for applications such as financial transactions, legal agreements, and securing critical infrastructure.