Iowa Barns Yesterday and Today, Including Silos, Corncribs, Homes, and Businesses

Review of: Iowa Barns Yesterday and Today, Including Silos, Corncribs, Homes, and Businesses by Karlene Kinger

American Home Life, 1880-1930: a Social History of Spaces and Services

Review of: American Home Life, 1880-1930: A Social History of Spaces and Services. Foy, Jessica H. and Schlereth, Thomas J., ed

Subliminal channels in high-speed signatures

One of the fundamental building blocks for achieving security in data networks is the use of digital signatures. A digital signature is a bit string which allows the receiver of a message to ensure that the message indeed originated from the apparent sender and has not been altered along the path. In certain cases, however, the functioning of signature schemes allows an adversary to additionally utilize the signature string as a hidden information channel. These channels are termed subliminal channels and have been known and tolerated since the 80s. Due to the recent progress in the development of high-speed signature algorithms, however, application scenarios for digital signatures become feasible that lead to a large exploitable bit rate for data exfiltration, given that the deployed signature scheme allows the utilization as subliminal channel. This thesis shows how certain high-speed signature schemes can be exploited to carry hidden information. In particular, we analyse the recent EdDSA signature scheme, which yields substantial future potential, as well as the class of Multivariate Quadratic (MQ) signature schemes. We discuss how an adversary can proceed to embed and recover subliminal information and what bit rate the adversary can achieve for transmitting hidden information. Scenarios like signed NTP broadcasts, signed sensor data transmissions and the TLS key exchange are depicted, where the existence of a subliminal channel gives rise to new attack possibilities threatening network security. To confirm these findings we discuss the results of performed experiments, which attest a considerable subliminal bandwidth to the analysed signature schemes. Furthermore, we depict several methods for preventing the exploitation of subliminal channels in EdDSA, but we have to conclude that none of them is viable in a practical situation, reinforcing the threats that originate from the described subliminal channels.von Alexander Rudolf HartlZusammenfassung in deutscher SpracheTechnische Universität Wien, Diplomarbeit, 2018(VLID)274766

Community risks for SARS-CoV-2 infection among fully vaccinated US adults by rurality: A retrospective cohort study from the National COVID Cohort Collaborative.

BackgroundWhile COVID-19 vaccines reduce adverse outcomes, post-vaccination SARS-CoV-2 infection remains problematic. We sought to identify community factors impacting risk for breakthrough infections (BTI) among fully vaccinated persons by rurality.MethodsWe conducted a retrospective cohort study of US adults sampled between January 1 and December 20, 2021, from the National COVID Cohort Collaborative (N3C). Using Kaplan-Meier and Cox-Proportional Hazards models adjusted for demographic differences and comorbid conditions, we assessed impact of rurality, county vaccine hesitancy, and county vaccination rates on risk of BTI over 180 days following two mRNA COVID-19 vaccinations between January 1 and September 21, 2021. Additionally, Cox Proportional Hazards models assessed the risk of infection among adults without documented vaccinations. We secondarily assessed the odds of hospitalization and adverse COVID-19 events based on vaccination status using multivariable logistic regression during the study period.ResultsOur study population included 566,128 vaccinated and 1,724,546 adults without documented vaccination. Among vaccinated persons, rurality was associated with an increased risk of BTI (adjusted hazard ratio [aHR] 1.53, 95% confidence interval [CI] 1.42-1.64, for urban-adjacent rural and 1.65, 1.42-1.91, for nonurban-adjacent rural) compared to urban dwellers. Compared to low vaccine-hesitant counties, higher risks of BTI were associated with medium (1.07, 1.02-1.12) and high (1.33, 1.23-1.43) vaccine-hesitant counties. Compared to counties with high vaccination rates, a higher risk of BTI was associated with dwelling in counties with low vaccination rates (1.34, 1.27-1.43) but not medium vaccination rates (1.00, 0.95-1.07). Community factors were also associated with higher odds of SARS-CoV-2 infection among persons without a documented vaccination. Vaccinated persons with SARS-CoV-2 infection during the study period had significantly lower odds of hospitalization and adverse events across all geographic areas and community exposures.ConclusionsOur findings suggest that community factors are associated with an increased risk of BTI, particularly in rural areas and counties with high vaccine hesitancy. Communities, such as those in rural and disproportionately vaccine hesitant areas, and certain groups at high risk for adverse breakthrough events, including immunosuppressed/compromised persons, should continue to receive public health focus, targeted interventions, and consistent guidance to help manage community spread as vaccination protection wanes