1,720,956 research outputs found
Measuring and Understanding TTL Violations in DNS Resolvers
No full textThe Domain Name System (DNS) is a scalable-distributed caching architecture where each DNS records are cached around several DNS servers distributed globally. DNS records include a time-to-live (TTL) value that dictates how long the record can be stored before it's evicted from the cache. TTL holds significant importance in aspects of DNS security, such as determining the caching period for DNSSEC-signed responses, as well as performance, like the responsiveness of CDN-managed domains. On a high level, TTL is crucial for ensuring efficient caching, load distribution, and network security in Domain Name System. Setting appropriate TTL values is a key aspect of DNS administration to ensure the reliable and efficient functioning of the Domain Name System. Therefore, it is crucial to measure how TTL violations occur in resolvers. But, assessing how DNS resolvers worldwide handle TTL is not easy and typically requires access to multiple nodes distributed globally. In this work, we introduce a novel methodology for measuring TTL violations in DNS resolvers leveraging a residential proxy service called Brightdata, enabling us to evaluate more than 27,000 resolvers across 9,500 Autonomous Systems (ASes). We found that 8.74% arbitrarily extends TTL among 8,524 resolvers that had atleast five distinct exit nodes. Additionally, we also find that the DNSSEC standard is being disregarded by 44.1% of DNSSEC-validating resolvers, as they continue to provide DNSSEC-signed responses even after the RRSIGs have expired.Master of ScienceThe Domain Name System (DNS) works as a global phonebook for the internet, helping your computer find websites by translating human-readable names into numerical IP addresses. This system uses a smart caching system spread across various servers worldwide to store DNS records. Each record comes with a time-to-live (TTL) value, essentially a timer that decides how long the information should stay in the cache before being replaced. TTL is crucial for both security and performance in the DNS world. It plays a role in securing responses and determines the responsiveness of load balancing schemes employed at Content Delivery Networks (CDNs). In simple terms, TTL ensures efficient caching, even network load, and overall security in the Domain Name System. For DNS to work smoothly, it's important to set the right TTL values and the resolvers to strictly honor the TTL. However, figuring out how well DNS servers follow these rules globally is challenging. In this study, we introduce a new way to measure TTL violations in DNS servers using a proxy service called Brightdata. This allows us to check over 27,000 servers across 9,500 networks. Our findings reveal that 8.74% of these servers extend TTL arbitrarily. Additionally, we discovered that 44.1% of servers that should be following a security standard (DNSSEC) are not doing so properly, providing signed responses even after they are supposed to expire. This research sheds light on how DNS servers around the world extend TTL and the potential performance and security risks involved
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Reliable and Decentralized Certificate Revocation via DNS: The Case for RevDNS
Get PDFThe Online Certificate Status Protocol’s long slide—after 25 years of soft-fail rules, privacy leakage, and shaky infrastructure—exposes a deeper failure in web-PKI revocation. Certificate Authorities increasingly route OCSP traffic through CDNs for speed, yet this recentralizes trust: our measurements show Akamai serves 62 percent of all revocation responses, creating single points of failure and betraying PKI’s decentralized ideals.
We present RevDNS, a DNS-based revocation scheme that drops CDN dependence while preserving real-time guarantees. Revoked serial numbers live in DNSSEC-signed TXT records; NSEC proofs allow aggressive negative caching, so recursive resolvers answer 99.8 percent of checks without bothering a CA. From 1.1 billion certificates and 5 million revocations, we find a large CA such as Let’s Encrypt can publish data for 612 million certificates in a 345 MB zone, with resolvers shouldering nearly every lookup.
Because answers piggyback on ordinary DNS lookups, RevDNS adds no latency and discloses no more about users than standard DNS traffic. By keeping revocation authority with CAs and avoiding fragile hacks like short-lived certificates, RevDNS delivers a durable, decentralized path for TLS revocation—one that finally aligns operational practicality with the web’s security ambitions.Published versio
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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