An annotated catalogue of the Odonata collection of Guido Lanfranco at the National Museum of Natural History in Malta

An annotated list of the Odonata collection of Guido Lanfranco, is provided. The specimens were captured between 1952 and 1971, and may be the oldest surviving specimens caught and still available in local collections from Malta. Almost all locally occurring species are represented, with some specimens collected in sites and habitats that have since been destroyed by urban development. A portion of the specimens bear no data labels and do not contribute to the knowledge of the distribution of the species. During the cataloguing process, specimens in poor condition were restored.peer-reviewe

Backdoors in Pseudorandom Number Generators:Possibility and Impossibility Results

Inspired by the Dual EC DBRG incident, Dodis et al. (Eurocrypt 2015) initiated the formal study of backdoored PRGs, showing that backdoored PRGs are equivalent to public key encryption schemes, giving constructions for backdoored PRGs (BPRGs), and showing how BPRGs can be “immunised” by careful post-processing of their outputs. In this paper, we continue the foundational line of work initiated by Dodis et al., providing both positive and negative results.We first revisit the backdoored PRG setting of Dodis et al., showing that PRGs can be more strongly backdoored than was previously envisaged. Specifically, we give efficient constructions of BPRGs for which, given a single generator output, Big Brother can recover the initial state and, therefore, all outputs of the BPRG. Moreover, our constructions are forward-secure in the traditional sense for a PRG, resolving an open question of Dodis et al. in the negative.We then turn to the question of the effectiveness of backdoors in robust PRNGs with input (c.f. Dodis et al., ACM-CCS 2013): generators in which the state can be regularly refreshed using an entropy source, and in which, provided sufficient entropy has been made available since the last refresh, the outputs will appear pseudorandom. The presence of a refresh procedure might suggest that Big Brother could be defeated, since he would not be able to predict the values of the PRNG state backwards or forwards through the high-entropy refreshes. Unfortunately, we show that this intuition is not correct: we are also able to construct robust PRNGs with input that are backdoored in a backwards sense. Namely, given a single output, Big Brother is able to rewind through a number of refresh operations to earlier “phases”, and recover all the generator’s outputs in those earlier phases.Finally, and ending on a positive note, we give an impossibility result: we provide a bound on the number of previous phases that Big Brother can compromise as a function of the state-size of the generator: smaller states provide more limited backdooring opportunities for Big Brother

A Surfeit of SSH Cipher Suites

This work presents a systematic analysis of symmetric encryption modes for SSH that are in use on the Internet, providing deployment statistics, new attacks, and security proofs for widely used modes. We report deployment statistics based on two Internet-wide scans of SSH servers conducted in late 2015 and early 2016. Dropbear and OpenSSH implementations dominate in our scans. From our first scan, we found 130,980 OpenSSH servers that are still vulnerable to the CBC-mode-specific attack of Albrecht et al. (IEEE S&P 2009), while we found a further 20,000 OpenSSH servers that are vulnerable to a new attack on CBC-mode that bypasses the counter-measures introduced in OpenSSH 5.2 to defeat the attack of Albrecht et al. At the same time, 886,449 Dropbear servers in our first scan are vulnerable to a variant of the original CBC-mode attack. On the positive side, we provide formal security analyses for other popular SSH encryption modes, namely ChaCha20-Poly1305, generic Encrypt-then-MAC, and AES-GCM. Our proofs hold for detailed pseudo-code descriptions of these algorithms as implemented in OpenSSH. Our proofs use a corrected and extended version of the "fragmented decryption" security model that was specifically developed for the SSH setting by Boldyreva et al. (Eurocrypt 2012). These proofs provide strong confidentiality and integrity guarantees for these alternatives to CBC-mode encryption in SSH. However, we also show that these alternatives do not meet additional, desirable notions of security (boundary-hiding under passive and active attacks, and denial-of-service resistance) that were formalised by Boldyreva et al

An overview of the dragonflies and damselflies of the Maltese Islands (Central Mediterranean) (Odonata)

Seventeen species of odonates have been recorded on the Maltese Islands of which Pantala flavescens represents a new record. Diagnostic features of the adult and larval stages of these species are described in this work. The work also combines findings from previous literature on Maltese Odonata with information gathered from fieldwork data in order to give an insight on the current situation of the Odonata of the Maltese Islands and serves as an identification guide to both adults and larvae of these insects. The anatomy and physiology of the larval and adult forms of these insects, which are discussed in this work, are adapted to the predatory lifestyle which they lead. The fact that odonate larvae frequent different habitats from adults helps to reduce competition for resources. Adult odonates can be found in a number of local habitats; mostly near freshwater but also brackish water bodies since freshwater is a scarce natural resource on the Maltese Islands. Global warming is affecting the distribution range of odonates in the Mediterranean - while some species may be on the decline, others which can thrive in hot dry environments are progressively being recorded in the Mediterranean and southern Europe, including the Maltese Islands. Relatively little work on the Odonata of the Maltese Islands has been done previous to the present work. Most of this involves listing of locally recorded species; very little research investigates odonate behaviour and distribution. No information exists as to why species such as Sympetrum striolatum, and Orthetrum cancellatum have become progressively uncommon in recent years, and therefore more research is required on the matter. Because of limiting water resources, freshwater habitats on the Maltese Islands are quickly drained of water, which may be used for agricultural purposes. This may tend to reduce species richness of local odonates. Biologists are now considering dragonflies as biological indicators of a healthy environment and make recommendations in order to preserve the habitats frequented by these insects.peer-reviewe

Distance learning : Is it worth the investment?

As human knowledge expands at an exponential rate, learning is increasingly becoming a lifelong endeavor. Careers and lives in the twenty-first century require constant learning, new education, and retraining. Thus, the nontraditional adult population in universities is increasing. Institutions pondering how to cope with an increasing student population and an ever shrinking budget can examine distance learning as a possible solution. Costs and benefits must be carefully considered in the areas of institution finances, the learning process, students, and instructors. Although many instructors gladly accept opportunities to teach in the distance learning environment, the majority of instructors still have concerns regarding four main issues related to distance learning: Teacher Compensation, Course Ownership, Course Creation, and Academic Integrity

On the Gold Standard for Security of Universal Steganography

While symmetric-key steganography is quite well understood both in the information-theoretic and in the computational setting, many fundamental questions about its public-key counterpart resist persistent attempts to solve them. The computational model for public-key steganography was proposed by von Ahn and Hopper in EUROCRYPT 2004. At TCC 2005, Backes and Cachin gave the first universal public-key stegosystem - i.e. one that works on all channels - achieving security against replayable chosen-covertext attacks (SS-RCCA) and asked whether security against non-replayable chosen-covertext attacks (SS-CCA) is achievable. Later, Hopper (ICALP 2005) provided such a stegosystem for every efficiently sampleable channel, but did not achieve universality. He posed the question whether universality and SS-CCA-security can be achieved simultaneously. No progress on this question has been achieved since more than a decade. In our work we solve Hopper's problem in a somehow complete manner: As our main positive result we design an SS-CCA-secure stegosystem that works for every memoryless channel. On the other hand, we prove that this result is the best possible in the context of universal steganography. We provide a family of 0-memoryless channels - where the already sent documents have only marginal influence on the current distribution - and prove that no SS-CCA-secure steganography for this family exists in the standard non-look-ahead model.Comment: EUROCRYPT 2018, llncs styl