Microservice Transition and its Granularity Problem: A Systematic Mapping Study

Microservices have gained wide recognition and acceptance in software industries as an emerging architectural style for autonomic, scalable, and more reliable computing. The transition to microservices has been highly motivated by the need for better alignment of technical design decisions with improving value potentials of architectures. Despite microservices' popularity, research still lacks disciplined understanding of transition and consensus on the principles and activities underlying "micro-ing" architectures. In this paper, we report on a systematic mapping study that consolidates various views, approaches and activities that commonly assist in the transition to microservices. The study aims to provide a better understanding of the transition; it also contributes a working definition of the transition and technical activities underlying it. We term the transition and technical activities leading to microservice architectures as microservitization. We then shed light on a fundamental problem of microservitization: microservice granularity and reasoning about its adaptation as first-class entities. This study reviews state-of-the-art and -practice related to reasoning about microservice granularity; it reviews modelling approaches, aspects considered, guidelines and processes used to reason about microservice granularity. This study identifies opportunities for future research and development related to reasoning about microservice granularity.Comment: 36 pages including references, 6 figures, and 3 table

Immersive Leadership Training for Physicians: Comparing Retrospective Pre- and Post-Test Virtual vs in-Person 6-Month Follow-Up of Learning

Claudia SP Fernandez,1 Georgina Adatsi,1 Caroline N Hays,1 Cheryl C Noble,2 Michelle Abel-Shoup,1 AnnaMarie Connolly3,4 1Department of Maternal and Child Health, UNC Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; 2Evaluation Consultant, CNoble Consulting, Scotts Valley, CA, USA; 3American College of Obstetricians and Gynecologists, Washington, DC, USA; 4Department of Obstetrics and Gynecology (Emeritus), UNC School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USACorrespondence: Claudia SP Fernandez, 426 Rosenau Hall, Maternal and Child Health Department, Gillings School of Global Public Health, 134 Dauer Drive, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA, Tel +1 919-451-6231, Fax +1-919-966-0458, Email [email protected]: Little is known about the long-term efficacy of virtual leadership training for physicians. This study compares two highly similar groups of Obstetricians-Gynecologists’ (OB-GYN) 6-month post-program changes in competency and skills after experiencing equity-centered leadership training in a virtual or in-person format.Participants and Methods: Using a retrospective pre- and post-test method, we collected 6-month post-program data on 14 competencies for knowledge gains and skills use, comparing the virtual cohort (2021, n = 22) to the in-person cohort (2022, n = 33) in 55 total participants. Qualitative data from open-ended feedback questions informed on skills relevancy and professional impact since program participation.Results: Data indicate strong, statistically significant knowledge and skills retention in both cohorts, with 63% of the virtual and 85% of the in-person participants responding. Data indicate participants report the course having a positive impact on their healthcare provision and nearly all report they made changes to their communication and leadership approaches in the 6-months after the program. 59% of the virtual and 55% of the in-person cohorts report new leadership opportunities since their participation and that the course helped prepare them for those roles. Qualitative data support the need for the training, specific elements of the training these physicians found particularly helpful, and that the learning was “sticky”, in that it stayed with them in the months post-program. There was a clear stated preference for in-person experiences.Conclusion: Either virtual or in-person leadership training can result in long-term (6-month) significant retention and application of knowledge and skills in physicians. While limited in size, this study suggests that in-person experiences seem to foster more effective bonds and also greater willingness to participate in post-program follow-up. Physicians find equity-centered leadership training to impact their subsequent communication and leadership practices and they report career benefits even in 6-month follow-up.Plain Language Summary: While physicians serve in many leadership roles in healthcare, leadership training is generally not part of their medical training. The American College of Obstetricians and Gynecologists (ACOG) Robert C. Cefalo Leadership Institute has provided an annual leadership training for obstetrician and gynecologist leaders since 2006. Our previous research has repeatedly shown the program is effective, with participants experiencing significant and impressive gains in leadership learning and skills development. The COVID-19 pandemic led to the 2021 program being held virtually with a return to an in-person format possible with the 2022 program. As such, the opportunity arose to compare the 6-month post-program learning and impact of these two formats, virtual versus in-person training, in two highly similar groups experiencing nearly identical program content. Both virtual and in-person participants rated their six-month post-program skill level/ability and skills use/implementation as significantly higher than pre-program and both groups noted the learning helped them be better physicians, communicators, and leaders. Additionally, many experienced new leadership opportunities in the 6-months post-program and most of those agreed that the program prepared them to take on those new roles. This study shows that our approach to physician leadership development is highly effective and that the learning demonstrated “stickiness” in that it persisted over time. While both virtual and in-person programs were highly effective, overwhelmingly the participants prefer in-person training to virtual training.Keywords: workforce development, physician leadership, learning retention, virtual vs in-person, equity-centered leadershi

Digital Communication Technology: Does Offering a Choice of Modality Improve Medication Adherence and Outcomes in a Persistent Asthma Population?

Background: Use of digital communication technology has shown potential to improve asthma adherence and outcomes. Few studies have looked at patient preference around mode of medication reminders used to improve and maintain asthma medication adherence. Objective: To determine if, in a population already receiving automated medication reminders, offering a choice for preferred mode of reminder (text, email, phone) would improve their adherence and asthma outcomes over a 1-year period. Methods: This was a pragmatic, randomized controlled trial conducted at Kaiser Permanente Colorado involving 7522 adult patients with persistent asthma. Study patients were randomized to receive usual care or their choice of medication reminder. Differences between the 2 groups in both medication adherence and asthma outcomes were then assessed over the following year. Results: Only 30% of those offered a choice of medication reminder modality responded by making a choice, with 52% preferring text messaging. There was less of a decrease in adherence rate over the 1-year period in those who made a choice regarding the mode of medication refill reminder. There was no difference in asthma outcomes between those who did make a choice compared with those who did not make a choice regarding the mode of medication refill reminder. Conclusion: In a patient population already receiving medication reminders, offering a choice about what type of technology-enabled asthma medication reminder patients wanted did not improve outcomes but did enable a subgroup to better maintain their medication adherence.Ye

Prospective Volumetric Assessment of the Liver on a Personal Computer by Nonradiologists Prior to Partial Hepatectomy

Ó The Author(s) 2010. This article is published with open access at Springerlink.com Background A small remnant liver volume is an important risk factor for posthepatectomy liver failure. ImageJ and OsiriX Ò are both free, open-source image processing software packages. The aim of the present study was to compare ImageJ and OsiriX Ò in performing prospective computed tomography (CT) volumetric analysis of the liver on a personal computer (PC) in patients undergoing major liver resection. Methods Patients scheduled for a right hemihepatectomy were eligible for inclusion. Two surgeons and one surgical trainee measured volumes of total liver, tumor, and future resection specimen prospectively with ImageJ and OsiriX Ò. A radiologist also measured these volumes with CT scanner-linked Aquarius iNtuition Ò software. Resection volumes were compared with the actual weights of the live

From Rerandomizability to Sequential Aggregation: Efficient Signature Schemes Based on SXDH Assumption

An aggregate signature allows one to generate a short aggregate of signatures from different signers on different messages. A sequential aggregate signature (SeqAS) scheme allows the signers to aggregate their individual signatures in a sequential manner. All existing SeqAS schemes that do not use the random oracle assumption either require a large public key or the security depends upon some non-standard interactive/static assumptions. In this paper, we present an efficient SeqAS scheme with constant-size public key under the SXDH assumption. In the process, we first obtain an optimized (and more efficient) variant of Libert et al\u27s randomizable signature scheme. While both the schemes are more efficient than the currently best ones that rely on some static assumption, they are only slightly costlier than the most efficient ones based on some interactive assumption

A Subversion-Resistant SNARK

While succinct non-interactive zero-knowledge arguments of knowledge (zk-SNARKs) are widely studied, the question of what happens when the CRS has been subverted has received little attention. In ASIACRYPT 2016, Bellare, Fuchsbauer and Scafuro showed the first negative and positive results in this direction, proving also that it is impossible to achieve subversion soundness and (even non-subversion) zero knowledge at the same time. On the positive side, they constructed an involved sound and subversion zero-knowledge argument system for NP. We show that Groth\u27s zk-SNARK for \textsc{Circuit-SAT} from EUROCRYPT 2016 can be made computationally knowledge-sound and perfectly composable Sub-ZK with minimal changes. We just require the CRS trapdoor to be extractable and the CRS to be publicly verifiable. To achieve the latter, we add some new elements to the CRS and construct an efficient CRS verification algorithm. We also provide a definitional framework for sound and Sub-ZK SNARKs and describe implementation results of the new Sub-ZK SNARK

Shorter Non-Interactive Zero-Knowledge Arguments and ZAPs for Algebraic Languages

We put forth a new framework for building pairing-based non-interactive zero- knowledge (NIZK) arguments for a wide class of algebraic languages, which are an extension of linear languages, containing disjunctions of linear languages and more. Our approach differs from the Groth-Sahai methodology, in that we rely on pairings to compile a $\Sigma$-protocol into a NIZK. Our framework enjoys a number of interesting features: – conceptual simplicity, parameters derive from the $\Sigma$-protocol; – proofs as short as resulting from the Fiat-Shamir heuristic applied to the underlying $\Sigma$-protocol; – fully adaptive soundness and perfect zero-knowledge in the common random string model with a single random group element as CRS; – yields simple and efficient two-round, public coin, publicly-verifiable perfect witness-indistinguishable (WI) arguments (ZAPs) in the plain model. To our knowledge, this is the first construction of two-rounds statistical witness-indistinguishable arguments from pairing assumptions. Our proof system relies on a new (static, falsifiable) assumption over pairing groups which generalizes the standard kernel Diffie-Hellman assumption in a natural way and holds in the generic group model (GGM) and in the algebraic group model (AGM). Replacing Groth-Sahai NIZKs with our new proof system allows to improve several important cryptographic primitives. In particular, we obtain the shortest tightly-secure structure-preserving signature scheme (which are a core component in anonymous credentials), the shortest tightly-secure quasi-adaptive NIZK with unbounded simulation soundness (which in turns implies the shortest tightly-mCCA-secure cryptosystem), and shorter ring signatures

Further Lower Bounds for Structure-Preserving Signatures in Asymmetric Bilinear Groups

Structure-Preserving Signatures (SPSs) are a useful tool for the design of modular cryptographic protocols. Recent series of works have shown that by limiting the message space of those schemes to the set of Diffie-Hellman (DH) pairs, it is possible to circumvent the known lower bounds in the Type-3 bilinear group setting thus obtaining the shortest signatures consisting of only 2 elements from the shorter source group. It has been shown that such a variant yields efficiency gains for some cryptographic constructions, including attribute-based signatures and direct anonymous attestation. Only the cases of signing a single DH pair or a DH pair and a vector from $\Z_p$ have been considered. Signing a vector of group elements is required for various applications of SPSs, especially if the aim is to forgo relying on heuristic assumptions. An open question is whether such an improved lower bound also applies to signing a vector of $\ell > 1$ messages. We answer this question negatively for schemes existentially unforgeable under an adaptive chosen-message attack (EUF-CMA) whereas we answer it positively for schemes existentially unforgeable under a random-message attack (EUF-RMA) and those which are existentially unforgeable under a combined chosen-random-message attack (EUF-CMA-RMA). The latter notion is a leeway between the two former notions where it allows the adversary to adaptively choose part of the message to be signed whereas the remaining part of the message is chosen uniformly at random by the signer. Another open question is whether strongly existentially unforgeable under an adaptive chosen-message attack (sEUF-CMA) schemes with 2-element signatures exist. We answer this question negatively, proving it is impossible to construct sEUF-CMA schemes with 2-element signatures even if the signature consists of elements from both source groups. On the other hand, we prove that sEUF-RMA and sEUF-CMA-RMA schemes with 2-element (unilateral) signatures are possible by giving constructions for those notions. Among other things, our findings show a gap between random-message/combined chosen-random-message security and chosen-message security in this setting

More Efficient Structure-Preserving Signatures - Or: Bypassing the Type-III Lower Bounds

Structure-preserving signatures are an important cryptographic primitive that is useful for the design of modular cryptographic protocols. It has been proven that structure-preserving signatures (in the most efficient Type-III bilinear group setting) have a lower bound of 3 group elements in the signature (which must include elements from both source groups) and require at least 2 pairing-product equations for verification. In this paper, we show that such lower bounds can be circumvented. In particular, we define the notion of Unilateral Structure-Preserving Signatures on Diffie-Hellman pairs (USPSDH) which are structure-preserving signatures in the efficient Type-III bilinear group setting with the message space being the set of Diffie-Hellman pairs, in the terminology of Abe et al. (Crypto 2010). The signatures in these schemes are elements of one of the source groups, i.e. unilateral, whereas the verification key elements\u27 are from the other source group. We construct a number of new structure-preserving signature schemes which bypass the Type-III lower bounds and hence they are much more efficient than all existing structure-preserving signature schemes. We also prove optimality of our constructions by proving lower bounds and giving some impossibility results. Our contribution can be summarized as follows: \begin{itemize} \item We construct two optimal randomizable CMA-secure schemes with signatures consisting of only 2 group elements from the first short source group and therefore our signatures are at least half the size of the best existing structure-preserving scheme for unilateral messages in the (most efficient) Type-III setting. Verifying signatures in our schemes requires, besides checking the well-formedness of the message, the evaluation of a single Pairing-Product Equation (PPE) and requires a fewer pairing evaluations than all existing structure-preserving signature schemes in the Type-III setting. Our first scheme has a feature that permits controlled randomizability (combined unforgeability) where the signer can restrict some messages such that signatures on those cannot be re-randomized which might be useful for some applications. \item We construct optimal strongly unforgeable CMA-secure one-time schemes with signatures consisting of 1 group element, and which can also sign a vector of messages while maintaining the same signature size. \item We give a one-time strongly unforgeable CMA-secure structure-preserving scheme that signs unilateral messages, i.e. messages in one of the source groups, whose efficiency matches the best existing optimal one-time scheme in every respect. \item We investigate some lower bounds and prove some impossibility results regarding this variant of structure-preserving signatures. \item We give an optimal (with signatures consisting of 2 group elements and verification requiring 1 pairing-product equation) fully randomizable CMA-secure partially structure-preserving scheme that simultaneously signs a Diffie-Hellman pair and a vector in $\Z^k_p$. \item As an example application of one of our schemes, we obtain efficient instantiations of randomizable weakly blind signatures which do not rely on random oracles. The latter is a building block that is used, for instance, in constructing Direct Anonymous Attestation (DAA) protocols, which are protocols deployed in practice. \end{itemize} Our results offer value along two fronts: On the practical side, our constructions are more efficient than existing ones and thus could lead to more efficient instantiations of many cryptographic protocols. On the theoretical side, our results serve as a proof that many of the lower bounds for the Type-III setting can be circumvented

Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion