1,720,966 research outputs found
PA1 Security on Release of Unverified Plaintext in Encrypt-then-MAC AE Schemes
Get PDFAt ASIACRYPT 2014, Andreeva et al. put forward a definition for security of authenticated encryption under release of unverified plaintext. They introduced two notions of plaintext awareness (PA1 and its stronger sibling PA2), suggested to be used in conjunction with confidentiality in case of release of unverified plaintext, as well as the notion of integrity under release of unverified plaintext (INT-RUP). Various efforts have been made to develop a unified model (e.g., Ashur et al., CRYPTO 2017, Chang et al., ToSC 2019(4)). With respect to the analysis of existing and new modes under release of unverified plaintext, most research however has focused on INT-RUP security only. Plaintext awareness is less studied and understood.
In this work, we take a detailed look at the original definitions of PA1 and PA2 security. We observe that the definitions leave too much room for interpretation, and claimed results such as PA1 security of Encrypt-then-MAC are unjustified. The core of the issue lies in the fact that PA1 security is necessarily tied to the implementation of the scheme. To resolve this, we present refined definitions of PA1 and PA2 security. We argue that even for these refined definitions, there is no implementation of Encrypt-and-MAC that is PA1 (nor PA2) secure. For MAC-then-Encrypt, results depend on the actual scheme, as we demonstrate using a negative result and a positive result (from literature, on Romulus-M). Furthermore, we formally prove for Encrypt-then-MAC that (i) there exist implementations that are PA1 insecure and (ii) there exist implementations that are PA1 secure. In other words, Encrypt-then-MAC is insecure under the old definition but secure under the new definition, provided a proper implementation is used. We apply this observation to Isap v2, finalist in the NIST Lightweight Cryptography competition, where we additionally deal with the complication that the same key is used for encryption and authentication
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
Beyond Birthday Bound Secure MAC in Faulty Nonce Model
Get PDFEncrypt-then-MAC (EtM) is a popular mode for authenticated encryption (AE). Unfortunately, almost all designs following the EtM paradigm, including the AE suites for TLS, are vulnerable against nonce misuse. A single repetition of the nonce value reveals the hash key, leading to a universal forgery attack. There are only two authenticated encryption schemes following the EtM paradigm which can resist nonce misuse attacks, the GCM-RUP (CRYPTO-17) and the GCM/2+ (INSCRYPT-12). However, they are secure only up to the birthday bound in the nonce respecting setting, resulting in a restriction on the data limit for a single key. In this paper we show that nEHtM, a nonce-based variant of EHtM (FSE-10) constructed using a block cipher, has a beyond birthday bound (BBB) unforgeable security that gracefully degrades under nonce misuse. We combine nEHtM with the CENC (FSE-06) mode of encryption using the EtM paradigm to realize a nonce-based AE, CWC+. CWC+ is very close (requiring only a few more xor operations) to the CWC AE scheme (FSE-04) and it not only provides BBB security but also gracefully degrading security on nonce misuse
Tight Security Analysis of the Public Permutation-Based PMAC_Plus
Get PDFYasuda proposed a variable input-length PRF in CRYPTO 2011, called \textsf{PMAC_Plus}, based on an -bit block cipher. \textsf{PMAC_Plus} is a rate- construction and inherits the well-known parallel network with a low additional cost. However, unlike , \textsf{PMAC_Plus} is secure roughly up to queries. Zhang et al. proposed \textsf{3kf9} in ASIACRYPT 2012, Naito proposed \textsf{LightMAC_Plus} in ASIACRYPT 2017, and Iwata et al. proposed \textsf{GCM-SIV2} in FSE 2017 -- all of them secure up to around queries. Their structural designs and corresponding security proofs were unified by Datta et al. in their framework {\em Double-block Hash-then-Sum} (\textsf{DbHtS}). Leurent et al. in CRYPTO 2018 and then Lee et al. in EUROCRYPT 2020 established a tight security bound of on \textsf{DbHtS}. That \textsf{PMAC_Plus} provides security for roughly up to queries is a consequence of this result. In this paper, we propose a public permutation-based variable input-length PRF called {\textsf{pPMAC_Plus}}. We show that {\textsf{pPMAC_Plus}} is secure against all adversaries that make at most queries. We also show that the bound is essentially tight. It is of note here that instantiation of each block cipher of {\textsf{pPMAC_Plus}} with the two-round iterated Even-Mansour cipher can yield a beyond the birthday bound secure PRF based on public permutations. Altogether, the solution incurs permutation calls, whereas our proposal requires only permutation calls, being the maximum number of message blocks
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
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
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