Pint, herramienta de simulación basada en trazas Pin

In the course of this project we have developed a set of programs to improve the correction and execution time of the gem5 simulator. For this, we moved the functional simulation step out of gem5 into an independent instrumented process to ensure correction in the functional stage and to provide a good execution speed (since the code will then be natively executed). This instrumentation is done by Pin. Also, in order to allow efficient communication between the processes despite the limitations imposed by Pin to the available tools, an IPC framework to allow message passing between the processes was developed. This framework uses lockless fifo queues over shared memory so the resulting slowdown is minimal.Izquierdo Riera, FB. (2012). Pint, herramienta de simulación basada en trazas Pin. http://hdl.handle.net/10251/18304.Archivo delegad

Clipaha: A Scheme to Perform Password Stretching on the Client

Password security relies heavily on the choice of password by the user but also on the one-way hash functions used to protect stored passwords. To compensate for the increased computing power of attackers, modern password hash functions like Argon2, have been made more complex in terms of computational power and memory requirements. Nowadays, the computation of such hash functions is performed usually by the server (or authenticator) instead of the client. Therefore, constrained Internet of Things devices cannot use such functions when authenticating users. Additionally, the load of computing such functions may expose servers to denial of service attacks. In this work, we discuss client-side hashing as an alternative. We propose Clipaha, a client-side hashing scheme that allows using high-security password hashing even on highly constrained server devices. Clipaha is robust to a broader range of attacks compared to previous work and covers important and complex usage scenarios. Our evaluation discusses critical aspects involved in client-side hashing. We also provide an implementation of Clipaha in the form of a web library and benchmark the library on different systems to understand its mixed JavaScript and WebAssembly approach\u27s limitations. Benchmarks show that our library is 50\% faster than similar libraries and can run on some devices where previous work fails

Methods for securely offloading password hashing to client

After a successful compromise, attackers may recover stored password hashes. These hashes may then be cracked to be able to use them on other services where the same or similar passwords may have been reused. A common method to secure such hashes is by using computationally expensive hash functions. This is usually done on the server and consumes a large amount of resources. Moreover, no such techniques exist for storing credentials on the client so that only the desired server can recover them.This invention aims to solve the issue of storing password hashes primarily in two ways:• moving the password hashing step to the client without introducing new security risks in theprocess; and• encrypting client stored hashes in a way that only the targeted server is able to recover them

Effectiveness of 23-valent pneumococcal polysaccharide vaccination in preventing community-acquired pneumonia hospitalization and severe outcomes in the elderly in Spain

Pneumococcal pneumonia is a serious cause of morbidity and mortality in the elderly, but investigation of the etiological agent of community-acquired pneumonia (CAP) is not possible in most hospitalized patients. The aim of this study was to estimate the effect of pneumococcal polysaccharide vaccination (PPSV23) in preventing CAP hospitalization and reducing the risk of intensive care unit admission (ICU) and fatal outcomes in hospitalized people aged ≥65 years. We made a multicenter case-control study in 20 Spanish hospitals during 2013-2014 and 2014-2015. We selected patients aged 65 years hospitalized with a diagnosis of pneumonia and controls matched by sex, age and date of hospitalization. Multivariate analysis was performed using conditional logistic regression to estimate vaccine effectiveness and unconditional logistic regression to evaluate the reduction in the risk of severe and fatal outcomes. 1895 cases and 1895 controls were included; 13.7% of cases and 14.4% of controls had received PPSV23 in the last five years. The effectiveness of PPSV23 in preventing CAP hospitalization was 15.2% (95% CI -3.1-30.3). The benefit of PPSV23 in avoiding ICU admission or death was 28.1% (95% CI -14.3-56.9) in all patients, 30.9% (95% CI -32.2-67.4) in immunocompetent patients and 26.9% (95% CI -38.6-64.8) in immunocompromised patients. In conclusion, PPSV23 showed a modest trend to avoidance of hospitalizations due to CAP and to the prevention of death or ICU admission in elderly patients hospitalized with a diagnosis of CAP