An integral security kernel

As the user base of the Internet has grown tremendously, the need for secure services has increased accordingly. Most secure protocols, in digital business and other fields, use a combination of symmetric and asymmetric cryptography, random generators and hash functions in order to achieve confidentiality, integrity, and authentication. Our proposal is an integral security kernel based on a powerful mathematical scheme from which all of these cryptographic facilities can be derived. The kernel requires very little resources and has the flexibility of being able to trade off speed, memory or security; therefore, it can be efficiently implemented in a wide spectrum of platforms and applications, either software, hardware or low cost devices. Additionally, the primitives are comparable in security and speed to well known standards.

A qualitative exploration of the impact of the economic recession in Spain on working, living and health conditions: reflections based on immigrant workers' experiences

Background: This study aimed to analyse how immigrant workers in Spain experienced changes in their working and employment conditions brought about Spain's economic recession and the impact of these changes on their living conditions and health status. Method: We conducted a grounded theory study. Data were obtained through six focus group discussions with immigrant workers (n = 44) from Colombia, Ecuador and Morocco, and two individual interviews with key informants from Romania living in Spain, selected by theoretical sample. Results: Three categories related to the crisis emerged – previous labour experiences, employment consequences and individual consequences – that show how immigrant workers in Spain (i) understand the change in employment and working conditions conditioned by their experiences in the period prior to the crisis, and (ii) experienced the deterioration in their quality of life and health as consequences of the worsening of employment and working conditions during times of economic recession. Conclusion: The negative impact of the financial crisis on immigrant workers may increase their social vulnerability, potentially leading to the failure of their migratory project and a return to their home countries. Policy makers should take measures to minimize the negative impact of economic crisis on the occupational health of migrant workers in order to strengthen social protection and promote health and well-being.

The Pliocene Mediterranean infilling of the Messinian Erosional Surface: New biostratigraphic data based on calcareous nannofossils (Bajo Segura Basin, SE Spain)

The Bajo Segura Basin (eastern Betic Cordillera) is a Mediterranean marginal basin where the Messinian Erosional Surface (MES), formed during the Messinian Salinity Crisis sea-level fall, is well developed. Overlying this major discontinuity the lower Pliocene transgressive sediments record the reflooding of the Mediterranean and the return to an open marine environment, the continental shelf being rebuilt after the Messinian erosion. The stratigraphic and biostratigraphic study of six sections allows two transgressive-regressive sequences filling the MES to be distinguished, correlated with the previously distinguished Mediterranean offshore seismic units. Ten calcareous nannofossil bioevents have been identified. The lower sequence can be dated according to nannofossil biozones NN12 to NN14 and the upper sequence by NN15 to NN16. The boundary between both lower Pliocene sedimentary sequences occur after the first common occurrence (FCO) of Discoaster asymmetricus found in the uppermost sediments of the lower sequence and before the first occurrence (FO) of Discoaster tamalis in the lowermost part of the upper sequence. Thus this sequence boundary can be estimated at between 4.1 and 4.0Ma ago.

The Impact of BIM on the Distribution of Cost and Return on Investment in UK Construction Projects

It has been widely documented that when Building Information Modelling (BIM) is used, there is a shift in effort to the design phase. Little investigation into the impact of this shift in effort has been done and how it impacts on costs. It can be difficult to justify the increased expenditure on BIM in a market that is heavily driven by costs. There are currently studies attempting to quantify the return on investment (ROI) for BIM for which these returns can be seen to balance out the shift in efforts and costs to the design phase. The studies however quantify the ROI based on the individual stakeholder’s investment without consideration for the impact that the use of BIM from their project partners may have on their own profitability. In this study, a questionnaire investigated opinions and experience of construction professionals, representing clients, consultants, designers and contractors, to determine fluctuations in costs by their magnitude and when they occur. These factors were examined more closely by interviewing senior members representing each of the stakeholder categories and comparing their experience in using BIM within environments where their project partners were also using BIM and when they were not. This determined the differences in how the use and the investment in BIM impacts on others and how costs are redistributed. This redistribution is not just through time but also between stakeholders and categories of costs. Some of these cost fluctuations and how the cost of BIM is currently financed are also highlighted in several case studies. The results show that the current distribution of costs set for traditional 2D delivery is hindering the potential success of BIM. There is also evidence that stakeholders who don’t use BIM may benefit financially from the BIM use of others and that collaborative BIM is significantly different to the use of ‘lonely’ BIM in terms of benefits and profitability.