1,720,975 research outputs found
Up-to-date Key Retrieval for Information Centric Networking
Full text linkInformation Centric Networking (ICN) leverages in-network caching to provide efficient data distribution and better performance by replicating contents in multiple nodes to bring content nearer the users. Since contents are stored and replicated into node caches, the content validity must be assured end-to-end. Each content object carries a digital signature to provide a proof of its integrity, authenticity, and provenance. However, the use of digital signatures requires a key management infrastructure to manage the key life cycle. To perform a proper signature verification, a node needs to know whether the signing key is valid or it has been revoked. This paper discusses how to retrieve up-to-date signing keys in the ICN scenario. In the usual public key infrastructure, the Certificate Revocation Lists (CRL) or the Online Certificate Status Protocol (OCSP) enable applications to obtain the revocation status of a certificate. However, the push-based distribution of Certificate Revocation Lists and the request/response paradigm of Online Certificate Status Protocol should be fit in the mechanism of named-data. We consider three possible approaches to distribute up-to-date keys in a similar way to the current CRL and OCSP. Then, we suggest a fourth protocol leveraging a set of distributed notaries, which naturally fits the ICN scenario. Finally, we evaluate the number and size of exchanged messages of each solution, and then we compare the methods considering the perceived latency by the end nodes and the throughput on the network links
On the Tradeoff between Performance and User Privacy in Information Centric Networking
Full text linkWidespread use of caching provides advantages for users and providers, such as reduced network latency, higher content availability, bandwidth reduction and server load balancing. In Information Centric Networking, the attention is shifted from users to content, which is addressed by its name and not by its location. Moreover, the content objects are stored as close as possible to the customers. Therefore, the cache has a central role for the improvement of the network performance but this is strictly related to the caching policy used. However, this comes at the price of increased tracing of users communication and users behavior to define an optimal caching policy. A malicious node could exploit such information to compromise the privacy of users. In this work, we compare different caching policies and we take the first steps for defining the tradeoff between caching performance and user privacy guarantee. In particular, we provide a way to implement prefetching and we define some bounds for the users' privacy in this context
Prenatal Mental Representations in Italian First-Time Mothers Before and During the COVID-19 Pandemic: A Study with Interviews on Maternal Representations During Pregnancy
Full text linkIntroductionPsychosocial risks increase the levels of not-integrated/ambivalent and restricted/disengaged representations during pregnancy, but no study has specifically analysed the impact of the COVID-19 pandemic on maternal representation styles.Objectives(1) to compare maternal representation styles in primiparous women who became pregnant before and during the COVID-19 pandemic and (2) to analyse the content of representation styles during the COVID-19 pandemic.MethodsA total of 37 Italian pregnant women were recruited from 2019 to 2021. The sample was divided into two groups: the pre-COVID-19 group (22 women, mean age = 33.14 years; SD = 3.78) and the COVID-19 group (15 women, mean age = 35.9 years; SD = 4.6). Interviews on maternal representations during pregnancy were administered and analysed for style and content. Results: Women during the COVID-19 pandemic reported more restricted/disengaged and less integrated/balanced representation styles than women pre-COVID-19. Content analysis showed that the COVID-19 pandemic led women to focus more on concrete aspects of pregnancy in lieu of emotional aspects, thus leading them to develop more restricted/disengaged representation styles. Conclusions for practiceIn future pandemics pregnant women should be supported in focusing their attention to emotions, sensations and fantasies about themselves as mothers and their children
A protocol for Metering Data Pseudonymization in Smart Grids
No full textA tradeoff between data collection needs and user privacy is of paramount importance in the Smart Grid. This paper
proposes a pseudonymization protocol for data gathered by the Smart Meters, which relies on a network infrastructure
and a dedicated set of nodes, called Privacy Preserving Nodes (PPNs). The network privacy is enforced by a separation of
duties: the PPNs perform data pseudonymization without having access to the measurements, which are masked by means
of a secret sharing scheme, while the entities accessing the data recover and relate the plain measurements generated by
the same meter along a time window of finite duration, but have no access to the meter identities.
The paper also provides an evaluation of the security and of the performance of the protocol, comparing it to the two
alternative encryption techniques which mask the measurements by means of the Chaum Mixing scheme or of an Identity Based Proxy Re-Encryption scheme
Optimal Content Prefetching in NDN Vehicle-to-Infrastructure Scenario
Full text linkData replication and in-network storage are two basic principles of the Information Centric Networking (ICN) framework in which caches spread out in the network can be used to store the most popular contents. This work shows how one of the ICN architectures, the Named Data Networking (NDN), with content pre-fetching can maximize the probability that a user retrieves the desired content in a Vehicle-to-Infrastructure scenario. We give an ILP formulation of the problem of optimally distributing content in the network nodes while accounting for the available storage capacity and the available link capacity. The optimization framework is then leveraged to evaluate the impact on content retrievability of topology- and network-related parameters as the number and mobility models of moving users, the size of the content catalog and the location of the available caches. Moreover, we show how the proposed model can be modified to find the minimum storage occupancy to achieve a given content retrievability level. The results obtained from the optimization model are finally validated against a Name Data Networking architecture through simulations in ndnSIM
Exploiting information centric networking to build an attacker-controlled content delivery network
Full text linkGoing Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
