We demonstrate a prototype implementation of a provably secure protocol that supports privacy-preserving mutual authentication between a server and a constrained device. Our proposed protocol is based on a physically unclonable function (PUF) and it is optimized for resource-constrained platforms. The reported results include a full protocol analysis, the design of its building blocks, their integration into a constrained device, and finally its performance evaluation. We show how to obtain efficient implementations for each of the building blocks of the protocol, including a fuzzy extractor with a novel helper-data construction technique, a truly random number generator (TRNG), and a pseudo-random function (PRF). The prototype is implemented on a SASEBO-GII board, using the on-board SRAM as the source of entropy for the PUF and the TRNG. We present three different implementations. The first two execute on a MSP430 soft-core processor and have a security level of 64-bit and 128-bit respectively. The third uses a hardware accelerator and has 128-bit security level. To our best knowledge, this work is the first effort to describe the end-to-end design and evaluation of a privacy-preserving PUF-based authentication protocol.

The use of Physically Unclonable Functions (PUFs) in cryptographic protocols attracted an increased interest over recent years. Since sound security analysis requires a concise specification of the alleged properties of the PUF, there have been numerous trials to provide formal security models for PUFs. However, all these approaches have been tailored to specific types of applications or specific PUF instantiations. For the sake of applicability, composability, and comparability, however, there is a strong need for a unified security model for PUFs (to satisfy, for example, a need to answer whether a future protocol requirements match a new and coming PUF realization properties). In this work, we propose a PUF model which generalizes various existing PUF models and includes security properties that have not been modeled so far. We prove the relation between some of the properties, and also discuss the relation of our model to existing ones.

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Malnutrition negatively affects the quality of life of patients with dysphagia. Despite the need for nutritional status assessment in patients with dysphagia, standard, effective nutritional assessments are not yet available, and the identification of optimal nutritional assessment items for patients with dysphagia is inadequate. We conducted a scoping review of the use of nutritional assessment items in adult patients with oropharyngeal and esophageal dysphagia. The MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials databases were searched to identify articles published in English within the last 30 years. Twenty-two studies met the inclusion criteria. Seven nutritional assessment categories were identified: body mass index (BMI), nutritional screening tool, anthropometric measurements, body composition, dietary assessment, blood biomarkers, and other. BMI and albumin were more commonly assessed in adults. The Global Leadership Initiative on Malnutrition (GLIM), defining new diagnostic criteria for malnutrition, includes the categories of BMI, nutritional screening tool, anthropometric measurements, body composition, and dietary assessment as its required components, but not the blood biomarkers and the “other” categories. We recommend assessing nutritional status, including GLIM criteria, in adult patients with dysphagia. This would standardize nutritional assessments in patients with dysphagia and allow future global comparisons of the prevalence and outcomes of malnutrition, as well as of appropriate interventions.

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version provides more efficient protocol than the preliminary version and includes a concrete analysis of efficiency with the previous results. We would like to thank Berkant Ustaoglu for invaluable comments on the preliminary version of this paper.

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