Self protecting data for de-perimeterised information sharing

The emergence of high-speed networks, Grid Computing, Service-Oriented Architectures, and an ever increasing ambient connection to mobile Internet has enabled an underpinning infrastructure for the development of dynamically formed, collaborative working groups known as Virtual Organisations (VOs). VOs provide strong motivation for investigation into the infrastructure, and in particular the security necessary to protect the information and resources shared within a VO, both while resident on local machines and when allowed to move beyond the secure boundary of a local organisational network perimeter and into the realm of the distributed VO. Traditional access control systems are perimeter- centric, meaning they apply the controls to both internal and external requests for access to information within or at the perimeter of their information system. • This paper presents the initial results of the JISC funded SPIDER project, being led by Cardiff University. Through case based example, the research investigates the limitations to granularity and persistent control over information when using the perimeter- centric approach in a collaborative working environment

Towards information sharing in virtual organisations: The development of an icon-based information control model

Today, innovation in information communication technology has encouraged contribution among different fields to tackle large-scale scientific problems or introduce novel inventories that, in both cases, demand extensive sharing of information among collaborating organisations in order to achieve the overall goal. Sharing information across different physical organisations, working as a single virtual organisation, raises a number of information security issues that limit the effectiveness, dynamism, and potential of collaborative working. Although extensive research has been conducted to provide secure information-sharing solutions within a single organisation, little research has investigated multi- organizational information-sharing environments where information requires to be protected but there are variations in information security needs and, in some cases, conflicts in applied information security controls. A key obstacle, the majority of research conducted in this area has overlooked, is not only the ability to govern remote access of users from one organisation to sensitive information stored in another organisation, but also having persistent control over owned information even after access has been granted and the information is either disseminated electronically, transformed into paper format, or even shared verbally. In addition, research was tailored to meet only specific research needs and address particular issues. Therefore, there is a lack of comprehensive, systematic approaches for controls on information usage shared electronically, regardless of specific circumstances. This paper aims to present a novel information control model that could keep information self-protected in dynamic collaborative environments by communicating information security needs along with the exchanged information using an Information Labelling Scheme. Based on SPIDER solution and Protective Commons, this scheme uses nine labelling icons (reflecting the protection type and level) associated with different information security controls (representing the information security mechanisms used to provide the protection). The model is demonstrated in the Microsoft Word 2007 application and a prototype has been developed as a plug-in software named Information Labelling Palette. It displays the nine self-explanatory icons in order for an information owner/user to label any information range within a single document using any icon. This consequently enforces the information security controls associated with the selected icon only into that particular range of electronic information, and secondly, communicates the information security needs to the recipient in a human-readable format, which would help keep recipients informed about how this information should be managed if printed out or shared verbally. Finally, the wide range of information security controls used in this proposed solution makes it widely applicable to meet the considerable diversity of organisations’ information security needs. Furthermore, it is believed to lay a solid foundation for future work in the area of information access control and control policy enforcement in collaborative environments

Information security requirements in patient-centred healthcare supporting systems

Enabling Patient-Centred (PC) care in modern healthcare requires the flow of medical information with the patient between different healthcare providers as they follow the patient's treatment plan. However, PC care threatens the stability of the balance of information security in the support systems since legacy systems fall short of attaining a security balance when sharing their information due to compromises made between its availability, integrity, and confidentiality. Results show that the main reason for this is that information security implementation in discrete legacy systems focused mainly on information confidentiality and integrity leaving availability a challenge in collaboration. Through an empirical study using domain analysis, observations, and interviews, this paper identifies a need for six information security requirements in legacy systems to cope with this situation in order to attain the security balance in systems supporting PC care implementation in modern healthcare

Measurement-Induced State Transitions in a Superconducting Qubit: Within the Rotating Wave Approximation

Superconducting qubits typically use a dispersive readout scheme, where a resonator is coupled to a qubit such that its frequency is qubit-state dependent. Measurement is performed by driving the resonator, where the transmitted resonator field yields information about the resonator frequency and thus the qubit state. Ideally, we could use arbitrarily strong resonator drives to achieve a target signal-to-noise ratio in the shortest possible time. However, experiments have shown that when the average resonator photon number exceeds a certain threshold, the qubit is excited out of its computational subspace, which we refer to as a measurement-induced state transition. These transitions degrade readout fidelity, and constitute leakage which precludes further operation of the qubit in, for example, error correction. Here we study these transitions using a transmon qubit by experimentally measuring their dependence on qubit frequency, average photon number, and qubit state, in the regime where the resonator frequency is lower than the qubit frequency. We observe signatures of resonant transitions between levels in the coupled qubit-resonator system that exhibit noisy behavior when measured repeatedly in time. We provide a semi-classical model of these transitions based on the rotating wave approximation and use it to predict the onset of state transitions in our experiments. Our results suggest the transmon is excited to levels near the top of its cosine potential following a state transition, where the charge dispersion of higher transmon levels explains the observed noisy behavior of state transitions. Moreover, occupation in these higher energy levels poses a major challenge for fast qubit reset

Overcoming leakage in scalable quantum error correction

Leakage of quantum information out of computational states into higher energy states represents a major challenge in the pursuit of quantum error correction (QEC). In a QEC circuit, leakage builds over time and spreads through multi-qubit interactions. This leads to correlated errors that degrade the exponential suppression of logical error with scale, challenging the feasibility of QEC as a path towards fault-tolerant quantum computation. Here, we demonstrate the execution of a distance-3 surface code and distance-21 bit-flip code on a Sycamore quantum processor where leakage is removed from all qubits in each cycle. This shortens the lifetime of leakage and curtails its ability to spread and induce correlated errors. We report a ten-fold reduction in steady-state leakage population on the data qubits encoding the logical state and an average leakage population of less than $1 \times 10^{-3}$ throughout the entire device. The leakage removal process itself efficiently returns leakage population back to the computational basis, and adding it to a code circuit prevents leakage from inducing correlated error across cycles, restoring a fundamental assumption of QEC. With this demonstration that leakage can be contained, we resolve a key challenge for practical QEC at scale.Comment: Main text: 7 pages, 5 figure

Readout of a quantum processor with high dynamic range Josephson parametric amplifiers

We demonstrate a high dynamic range Josephson parametric amplifier (JPA) in which the active nonlinear element is implemented using an array of rf-SQUIDs. The device is matched to the 50 $\Omega$ environment with a Klopfenstein-taper impedance transformer and achieves a bandwidth of 250-300 MHz, with input saturation powers up to -95 dBm at 20 dB gain. A 54-qubit Sycamore processor was used to benchmark these devices, providing a calibration for readout power, an estimate of amplifier added noise, and a platform for comparison against standard impedance matched parametric amplifiers with a single dc-SQUID. We find that the high power rf-SQUID array design has no adverse effect on system noise, readout fidelity, or qubit dephasing, and we estimate an upper bound on amplifier added noise at 1.6 times the quantum limit. Lastly, amplifiers with this design show no degradation in readout fidelity due to gain compression, which can occur in multi-tone multiplexed readout with traditional JPAs.Comment: 9 pages, 8 figure

Measurement-induced entanglement and teleportation on a noisy quantum processor

Measurement has a special role in quantum theory: by collapsing the wavefunction it can enable phenomena such as teleportation and thereby alter the "arrow of time" that constrains unitary evolution. When integrated in many-body dynamics, measurements can lead to emergent patterns of quantum information in space-time that go beyond established paradigms for characterizing phases, either in or out of equilibrium. On present-day NISQ processors, the experimental realization of this physics is challenging due to noise, hardware limitations, and the stochastic nature of quantum measurement. Here we address each of these experimental challenges and investigate measurement-induced quantum information phases on up to 70 superconducting qubits. By leveraging the interchangeability of space and time, we use a duality mapping, to avoid mid-circuit measurement and access different manifestations of the underlying phases -- from entanglement scaling to measurement-induced teleportation -- in a unified way. We obtain finite-size signatures of a phase transition with a decoding protocol that correlates the experimental measurement record with classical simulation data. The phases display sharply different sensitivity to noise, which we exploit to turn an inherent hardware limitation into a useful diagnostic. Our work demonstrates an approach to realize measurement-induced physics at scales that are at the limits of current NISQ processors

Non-Abelian braiding of graph vertices in a superconducting processor

Indistinguishability of particles is a fundamental principle of quantum mechanics. For all elementary and quasiparticles observed to date - including fermions, bosons, and Abelian anyons - this principle guarantees that the braiding of identical particles leaves the system unchanged. However, in two spatial dimensions, an intriguing possibility exists: braiding of non-Abelian anyons causes rotations in a space of topologically degenerate wavefunctions. Hence, it can change the observables of the system without violating the principle of indistinguishability. Despite the well developed mathematical description of non-Abelian anyons and numerous theoretical proposals, the experimental observation of their exchange statistics has remained elusive for decades. Controllable many-body quantum states generated on quantum processors offer another path for exploring these fundamental phenomena. While efforts on conventional solid-state platforms typically involve Hamiltonian dynamics of quasi-particles, superconducting quantum processors allow for directly manipulating the many-body wavefunction via unitary gates. Building on predictions that stabilizer codes can host projective non-Abelian Ising anyons, we implement a generalized stabilizer code and unitary protocol to create and braid them. This allows us to experimentally verify the fusion rules of the anyons and braid them to realize their statistics. We then study the prospect of employing the anyons for quantum computation and utilize braiding to create an entangled state of anyons encoding three logical qubits. Our work provides new insights about non-Abelian braiding and - through the future inclusion of error correction to achieve topological protection - could open a path toward fault-tolerant quantum computing