Information Assurance & Security (IAS) is a dynamic domain which changes continuously in response to the evolution of society, business needs and technology. This paper proposes a Reference Model of Information Assurance & Security (RMIAS), which endeavours to address the recent trends in the IAS evolution, namely diversification and deperimetrisation. The model incorporates four dimensions: Information System Security Life Cycle, Information Taxonomy, Security Goals and Security Countermeasures. In addition to the descriptive knowledge, the RMIAS embeds the methodological knowledge. A case study demonstrates how the RMIAS assists with the development and revision of an Information Security Policy Document.

Practical quantum computing will require error rates well below those achievable with physical qubits. Quantum error correction1,2 offers a path to algorithmically relevant error rates by encoding logical qubits within many physical qubits, for which increasing the number of physical qubits enhances protection against physical errors. However, introducing more qubits also increases the number of error sources, so the density of errors must be sufficiently low for logical performance to improve with increasing code size. Here we report the measurement of logical qubit performance scaling across several code sizes, and demonstrate that our system of superconducting qubits has sufficient performance to overcome the additional errors from increasing qubit number. We find that our distance-5 surface code logical qubit modestly outperforms an ensemble of distance-3 logical qubits on average, in terms of both logical error probability over 25 cycles and logical error per cycle ((2.914 ± 0.016)% compared to (3.028 ± 0.023)%). To investigate damaging, low-probability error sources, we run a distance-25 repetition code and observe a 1.7 × 10−6 logical error per cycle floor set by a single high-energy event (1.6 × 10−7 excluding this event). We accurately model our experiment, extracting error budgets that highlight the biggest challenges for future systems. These results mark an experimental demonstration in which quantum error correction begins to improve performance with increasing qubit number, illuminating the path to reaching the logical error rates required for computation.

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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 perimetercentric, 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 perimetercentric approach in a collaborative working environment.

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