Cryptographic properties of Boolean functions defining elementary cellular automata

In this work, the algebraic properties of the local transition functions of elementary cellular automata (ECA) were analysed. Specifically, a classification of such cellular automata was done according to their algebraic degree, the balancedness, the resiliency, nonlinearity, the propagation criterion and the existence of non-zero linear structures. It is shown that there is not any ECA satisfying all properties at the same time

Faster Correlation Attack on Bluetooth Keystream Generator E0

Abstract. We study both distinguishing and key-recovery attacks against E0, the keystream generator used in Bluetooth by means of correlation. First, a powerful computation method of correlations is formulated by a recursive expression, which makes it easier to calculate correlations of the finite state machine output sequences up to 26 bits for E0 and allows us to verify the two known correlations to be the largest for the first time. Second, we apply the concept of convolution to the analysis of the distinguisher based on all correlations, and propose an efficient distinguisher due to the linear dependency of the largest correlations. Last, we propose a novel maximum likelihood decoding algorithm based on fast Walsh transform to recover the closest codeword for any linear code of dimension L and length n. It requires time O(n + L · 2 L) and memory min(n, 2 L). This can speed up many attacks such as fast correlation attacks. We apply it to E0, and our best key-recovery attack works in 2 39 time given 2 39 consecutive bits after O(2 37) precomputation. This is the best known attack against E0 so far.

Feasibility and tolerability of ophthalmic virtual reality as a medical communication tool in children and young people

Purpose Virtual reality (VR) can be useful in explaining diseases and complications that affect children in order to improve medical communications with this vulnerable patient group. So far, children and young people’s responses to high-end medical VR environments have never been assessed. Methods An unprecedented number of 320 children and young people were given the opportunity to interact with a VR application displaying original ophthalmic volume data via a commercially available tethered head-mounted display (HMD). Participants completed three surveys: demographics and experience with VR, usability and perceived utility of this technology and the Simulator Sickness Questionnaire. The second survey also probed participants for suggestions on improvements and whether this system could be useful for increasing engagement in science. Results A total of 206 sets of surveys were received. 165 children and young people (84 female) aged 12–18 years (mean, 15 years) completed surveys that could be used for analysis. 69 participants (47.59%) were VR-naïve, and 76 (52.41%) reported that they had previous VR experience. Results show that VR facilitated understanding of ophthalmological complications and was reasonably tolerated. Lastly, exposure to VR raised children and young people’s awareness and interest in science. Conclusions The VR platform used was successfully utilized and was well accepted in children to display and interact with volume-rendered 3D ophthalmological data. Virtual reality (VR) is suitable as a novel image display platform in ophthalmology to engage children and young people

Environmental Monitoring Plan

The purpose of the environmental monitoring plan (EMP) is to promote the early identification of, and response to, potential adverse environmental impacts associated with DOE operations. Environmental monitoring supports the Integrated Safety Management System (ISMS) to detect, characterize, and respond to releases from DOE activities; assess impacts; estimate dispersal patterns in the environment; characterize the pathways of exposure to members of the public; characterize the exposures and doses to individuals and to the population; and to evaluate the potential impacts to the biota in the vicinity of the DOE activity. In addition, the EMP addresses the analytical work supporting environmental monitoring to ensure the following: (1) A consistent system for collecting, assessing, and documenting environmental data of known and documented quality; (2) A validated and consistent approach for sampling and analysis of radionuclide samples to ensure laboratory data meets program-specific needs and requirements within the framework of a performance-based approach for analytical laboratory work; and (3) An integrated sampling approach to avoid duplicative data collection. Until recently, environmental monitoring at Lawrence Livermore National Laboratory (LLNL) was required by DOE Order 5400.1, which was canceled in January 2003. LLNL is in the process of adopting the ISO 14001 Environmental Management Systems standard, which contains requirements to perform and document environmental monitoring. The ISO 14001 standard is not as prescriptive as DOE Order 5400.1, which expressly required an EMP. LLNL will continue to prepare the EMP because it provides an organizational framework for ensuring that the work is conducted appropriately. The environmental monitoring addressed by the plan includes preoperational characterization and assessment, and effluent and surveillance monitoring. Additional environmental monitoring is conducted at LLNL as part of the compliance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, also known as Superfund). This EMP does not address the technical requirements for such monitoring