Astrolabous: A Universally Composable Time Lock Encryption Scheme

In this work, we study the Time-Lock Encryption (TLE) cryptographic primitive. The concept of TLE involves a party initiating the encryption of a message that one can only decrypt after a certain amount of time has elapsed. Following the Universal Composability (UC) paradigm introduced by Canetti [IEEE FOCS 2001], we formally abstract the concept of TLE into an ideal functionality. In addition, we provide a standalone definition for secure TLE schemes in a game-based style and we devise a hybrid protocol that relies on such a secure TLE scheme. We show that if the underlying TLE scheme satisfies the standalone game-based security definition, then our hybrid protocol UC realises the TLE functionality in the random oracle model. Finally, we present Astrolabous, a TLE construction that satisfies our security definition, leading to the first UC realization of the TLE functionality. Interestingly, it is hard to prove UC secure any of the TLE construction proposed in the literature. The reason behind this difficulty relates to the UC framework itself. Intuitively, to capture semantic security, no information should be leaked regarding the plaintext in the ideal world, thus the ciphertext should not contain any information relating to the message. On the other hand, all ciphertexts will eventually open, resulting in a trivial distinction of the real from the ideal world in the standard model. We overcome this limitation by extending any secure TLE construction adopting the techniques of Nielsen [CRYPTO 2002] in the random oracle model. Specifically, the description of the extended TLE algorithms includes calls to the random oracle, allowing our simulator to equivocate. This extension can be applied to any TLE algorithm that satisfies our standalone game-based security definition, and in particular to Astrolabous

Penetrating Abdominal Injuries: Management Controversies

Penetrating abdominal injuries have been traditionally managed by routine laparotomy. New understanding of trajectories, potential for organ injury, and correlation with advanced radiographic imaging has allowed a shift towards non-operative management of appropriate cases. Although a selective approach has been established for stab wounds, the management of abdominal gunshot wounds remains a matter of controversy. In this chapter we describe the rationale and methodology of selecting patients for non-operative management. We also discuss additional controversial issues, as related to antibiotic prophylaxis, management of asymptomatic thoracoabdominal injuries, and the use of colostomy vs. primary repair for colon injuries

Penetrating abdominal injuries: management controversies

Penetrating abdominal injuries have been traditionally managed by routine laparotomy. New understanding of trajectories, potential for organ injury, and correlation with advanced radiographic imaging has allowed a shift towards non-operative management of appropriate cases. Although a selective approach has been established for stab wounds, the management of abdominal gunshot wounds remains a matter of controversy. In this chapter we describe the rationale and methodology of selecting patients for non-operative management. We also discuss additional controversial issues, as related to antibiotic prophylaxis, management of asymptomatic thoracoabdominal injuries, and the use of colostomy vs. primary repair for colon injuries

An archaeometric study of Hellenistic glass vessels: evidence for multiple sources

In the present study, 53 glass fragments from core-formed vessels and 3 glass beads are investigated using SEM/EDX, EPMA and LA-ICP-MS. All samples were excavated in the Latin settlement of Satricum in central west Italy and apart from two, were found in the so-called fourth–third c. BC Hellenistic Votive deposit, also known as Votive Deposit III, discovered in front of the sanctuary of Mater Matuta on top of the acropolis. The analytical results indicate that the glass from Satricum is a typical soda-lime-silica type with natron used as a flux. Its chemical compositions display a relatively low compositional variation. Small differences in the concentrations of major and minor oxides (SiO2, Al2O3, CaO and Fe2O3) and in trace elements (Sr, Zr and Nd) between individual samples suggest the use of different types of raw materials, especially sand. In turn, this suggests that the glass derived from more than one glass making centre. The combined investigation of colourants (Co, Cu and Mn) reinforces and confirms the idea that glass from Satricum was made using different manufacturing traditions during the Hellenistic period

Universally Composable Simultaneous Broadcast against a Dishonest Majority and Applications

Simultaneous broadcast (SBC) protocols, introduced in [Chor et al., FOCS 1985], constitute a special class of broadcast channels which, besides consistency, guarantee that all senders broadcast their messages independently of the messages broadcast by other parties. SBC has proved extremely useful in the design of various distributed computing constructions (e.g., multiparty computation, coin flipping, electronic voting, fair bidding). As with any communication channel, it is crucial that SBC security is composable, i.e., it is preserved under concurrent protocol executions. The work of [Hevia, SCN 2006] proposes a formal treatment of SBC in the state-of-the-art Universal Composability (UC) framework [Canetti, FOCS 2001] and a construction secure assuming an honest majority. In this work, we provide a comprehensive revision of SBC in the UC setting and improve the results of [Hevia, SCN 2006]. In particular, we present a new SBC functionality that captures both simultaneity and liveness by considering a broadcast period such that (i) within this period all messages are broadcast independently and (ii) after the period ends, the session is terminated without requiring full participation of all parties. Next, we employ time-lock encryption (TLE) over a standard broadcast channel to devise an SBC protocol that realizes our functionality against any adaptive adversary corrupting up to all-but-one parties. In our study, we capture synchronicity via a global clock [Katz et al., TCC 2013], thus lifting the restrictions of the original synchronous communication setting used in [Hevia, SCN 2006]. As a building block of independent interest, we prove the first TLE protocol that is adaptively secure in the UC setting, strengthening the main result of [Arapinis et al., ASIACRYPT 2021]. Finally, we formally exhibit the power of our SBC construction in the design of UC-secure applications by presenting two interesting use cases: (i) distributed generation of uniform random strings, and (ii) decentralized electronic voting systems, without the presence of a special trusted party

A contribution to the study of post-depositional alterations of pottery using TL dating analysis

In luminescence dating, the potassium concentration significantly contributes to the dose rate value in the age estimation. Within this study, fine-grain thermoluminescence dating has been applied on sherds of calcareous pottery of known age, excavated at a Roman site in Mallorca, Spain. For those of the samples that showed signs of severe potassium leaching, according to chemical and mineralogical examination, the thermoluminescence analysis provided overestimated dates. By using the known archaeological age of the samples, a corrected dose rate value can be estimated which provides the potassium concentration averaged for the burial period. Finally, a step-like model can then be used to estimate the fraction of the burial period after which most of the alteration effects took place

Common Adverse Effects of Anti-TNF Agents on Gestation

Autoimmune disease has affected up to 50 million Americans, according to the American Autoimmune Related Diseases Association (AARDA) and 75 percent of those affected are women. These inflammatory diseases have variable activity and a lot of women will have to undergo major therapies during and after pregnancy. Many of the women suffering from these disease will improve during gestation. However a lot of women will require continuation of disease-modifying therapies (i.e., biological therapies) throughout pregnancy and post-partum involving many risks. In the past decade all gaze turned to biological therapies, as an attempt, to obtain even more effective medications in order to suppress the exacerbation of autoimmune disease, even at the most unfit circumstances such as pregnancy. The results are both satisfying and promising since increasingly proven thoughts prevail on making anti-TNF agents first-line medications, clearing up the limited knowledge over human influence. The purpose of this review is to summarize the results of the reports with the highest and representative range of patients of the last decade involving the use of anti-TNF agents during pregnancy

MCMix: Anonymous Messaging via Secure Multiparty Computation

We present ‘MCMix’, an anonymous messaging system that completely hides communication metadata and can scale in the order of hundreds of thousands of users. Our approach is to isolate two suitable functionalities, called dialing and conversation, that when used in succession realize anonymous messaging. With this as a starting point, we apply secure multiparty computation (``MC\u27\u27 or MPC) and proceed to realize them. We present an implementation using a prevalent MPC system (Sharemind) that is competitive in terms of latency with previous messaging systems that only offer much weaker privacy guarantees. Our solution can be instantiated in a variety of different ways with different MPC implementations, overall illustrating how MPC is a viable and competitive alternative to mix-nets and DC-nets for anonymous communication

Measuring productivities for the 38 OECD member countries: an input-output modelling approach

Using a multisectoral model and the latest data from the OECD Input-Output Tables (IOTs2021 ed.), this article estimates labour and capital productivities of the 38 OECD member countries. As measures of the productivity of labour, we consider the inverse of the vertically integrated labour coefficients, while Perron–Frobenius theorems are employed so as to measure capital productivity. In this respect, the productive technologies and the intersectoral relationships of each economy are taken into account. We further investigate the relationship between productivity, economic efficiency and living standards. Findings indicate that the impact of capital productivity on higher living standards depends on the evolutionary and institutional background of the economy at hand