Arion: Arithmetization-Oriented Permutation and Hashing from Generalized Triangular Dynamical Systems

In this paper we propose the (keyed) permutation Arion and the hash function ArionHash over $\mathbb{F}_p$ for odd and particularly large primes. The design of Arion is based on the newly introduced Generalized Triangular Dynamical System (GTDS), which provides a new algebraic framework for constructing (keyed) permutation using polynomials over a finite field. At round level Arion is the first design which is instantiated using the new GTDS. We provide extensive security analysis of our construction including algebraic cryptanalysis (e.g. interpolation and Groebner basis attacks) that are particularly decisive in assessing the security of permutations and hash functions over $\mathbb{F}_p$. From a application perspective, ArionHash is aimed for efficient implementation in zkSNARK protocols and Zero-Knowledge proof systems. For this purpose, we exploit that CCZ-equivalence of graphs can lead to a more efficient implementation of Arithmetization-Oriented primitives. We compare the efficiency of ArionHash in R1CS and Plonk settings with other hash functions such as Poseidon, Anemoi and Griffin. For demonstrating the practical efficiency of ArionHash we implemented it with the zkSNARK libraries libsnark and Dusk Network Plonk. Our result shows that ArionHash is significantly faster than Poseidon - a hash function designed for zero-knowledge proof systems. We also found that an aggressive version of ArionHash is considerably faster than Anemoi and Griffin in a practical zkSNARK setting

The Horn Fragment of Branching Algebra

Branching Algebra is the natural branching-time generalization of Allen's Interval Algebra. As in the linear case, the consistency problem for Branching Algebra is NP-hard. Being relatively new, however, not much is known about the computational behaviour of the consistency problem of its sub-algebras, except in the case of the recently found subset of convex branching relations, for which the consistency of a network can be tested via path consistency and it is therefore deterministic polynomial. In this paper, following Nebel and Bürckert, we define the Horn fragment of Branching Algebra, and prove that it is a sub-algebra of the latter, being closed under inverse, intersection, and composition, that it strictly contains both the convex fragment of Branching Algebra and the Horn fragment of Interval Algebra, and that its consistency problem can be decided via path consistency. Finally, we experimentally prove that the Horn fragment of Branching Algebra can be used as an heuristic for checking the consistency of a generic network with a considerable improvement over the convex subset

semi automatic derivation of channel network from a high resolution dtm the example of an italian alpine region

AbstractHigh-resolution digital terrain models (HR-DTMs) of regional coverage open interesting scenarios for the analysis of landscape, including derivation and analysis of channel network. In this study, we present the derivation of the channel network from a HR-DTM for the Autonomous Province of Trento. A preliminary automatic extraction of the raw channel network was conducted using a curvature-based algorithm applied to a 4 m resolution DTM derived from an airborne LiDAR survey carried out in 2006. The raw channel network automatically extracted from the HR-DTM underwent a supervised control to check the spatial pattern of the hydrographic network. The supervised control was carried out by means of different informative layers (i.e. geomorphometric indexes, orthophoto imagery and technical cartography) resulting in an accurate and fine-scale channel network

Sigurnost rada u anatomskom laboratoriju s formalinom i inovativno praćenje procjene profesionalne izloženosti formaldehidu

This review is directed at preventive health professionals, anatomic pathologists and technicians to focus their attention on the rapidly growing field of safe formalin practices. An updated overview of the most recent improvements in preventive measures versus formaldehyde (FA) in the anatomic pathology laboratories (APL) is provided. The occupational hygienist role and the required knowledge for a modern and clear occupational exposure assessment are described. Real-time, in-continuous, commercial analyzers for repeated FA exposure assessment are considered to evaluate technical changes in air monitoring programs, introduced to mitigate FA emissions, in compliance with the adopted limit values. To better choose the adequate instrumentation, the main features of each FA monitoring instrument recently introduced on the market are listed. Moreover, the main features of the modern workflow setting in APL are summarized. A computer-based scientific and non-scientific reports search by key-words was performed on PubMed, Web of Science, Google Scholar and Google Patents databases, querying the following topics: i) grossing workstation for ergonomic layout, ii) commercially available direct reading tools to measure formalin, iii) real-time, in-continuous FA monitoring instruments for sale. This review represents a useful tool to summarize the technical requirements and expert know-how necessary to minimize FA emissions and produce an exhaustive FA assessment in the APL.Ovaj pregled usmjeren je na preventivne zdravstvene radnike, anatomske patologe i tehničare kako bi svoju pozornost usredotočili na brzo rastuće područje sigurnih formalinskih praksi. Ažurirani pregled nudi najnovija poboljšanja preventivnih mjera u odnosu na formaldehid (FA) u laboratorijima za anatomsku patologiju (APL). Opisana je uloga higijeničara na radu i potrebna znanja za modernu i jasnu procjenu izloženosti na radu. Komercijalni analizatori u stvarnom vremenu za kontinuiranu procjenu izloženosti FA razmatraju se za procjenu tehničkih promjena u programima praćenja zraka, uvedenim radi ublažavanja emisija FA, u skladu s prihvaćenim graničnim vrijednostima. Kako bi se bolje odabrala odgovarajuća instrumentacija, navedene su glavne značajke svakog instrumenta za praćenje FA koji je nedavno predstavljen na tržištu. Štoviše, sažete su glavne značajke suvremenih postavki tijeka rada u APL-u. Računalno zasnovano pretraživanje znanstvenih i neznanstvenih izvješća po ključnim riječima provedeno je u bazama podataka PubMed, Web of Science, Google Scholar i Google Patents, s težištem na sljedeće teme: i) prikupljanje radnih stanica za ergonomski raspored, ii) komercijalno dostupni alati za izravno očitanje mjerenja formalina, iii) instrumenti za kontinuirano praćenje FA u stvarnom vremenu u prodaji. Ovaj pregled predstavlja koristan alat za sažimanje tehničkih zahtjeva i stručnog znanja potrebnog za minimiziranje emisija FA i izradu iscrpne procjene FA u APL-u

On Efficient and Secure Compression Modes for Arithmetization-Oriented Hashing

ZK-SNARKs are advanced cryptographic protocols used in private verifiable computation: modern SNARKs allow to encode the invariants of an arithmetic circuit over some large prime field in an appropriate NP language, from which a zero-knowlege short non-interactive argument of knowledge is built. Due to the high cost of proof generation, ZK-SNARKs for large constraint systems are inpractical. ZK-SNARKs are used in privacy-oriented blockchains such as Filecoin, ZCash and Monero, to verify Merkle tree opening proofs, which in turn requires computing a fixed-input-length (FIL) cryptographic compression function. As classical, bit-oriented hash functions like SHA-2 require huge constraint systems, Arithmetization-Oriented (AO) compression functions have emerged to fill the gap. Usually, AO compression functions are obtained by applying the Sponge hashing mode on a fixed-key permutation: while this avoids the cost of dynamic key scheduling, AO schedulers are often cheap to compute, making the exploration of AO compression functions based directly on blockciphers a topic of practical interest. In this work, we first adapt notions related to classical hash functions and their security notions to the AO syntax, and inspired by the classical PGV modes, we propose AO PGV-LC and AO PGV-ELC, two blockcipher-based FIL compression modes with parametrizable input and output sizes. In the ideal cipher model, we prove the collision and preimage resistance of both our modes, and give bounds for collision and opening resistance over Merkle trees of arbitrary arity. We then experimentally compare the AO PGV-LC mode over the Hades-MiMC blockcipher with its popular Sponge instantiation, Poseidon. The resulting construction, called Poseidon-DM, is $2$-$5\times$ faster than Poseidon in native computations, and $15$-$35\%$ faster in generating Merkle tree proofs over the Groth16 SNARK framework, depending on the tree arity. In particular, proof generation for an $8$-ary tree over Poseidon-DM is $2.5\times$ faster than for a binary tree with the same capacity over Poseidon. Finally, in an effort to further exploit the benefits of wide trees, we propose a new strategy to obtain a compact R1CS constraint system for Merkle trees with arbitrary arity

Ažuriranje podataka o prožimanju zaštitnih medicinskih rukavica antineoplastičnim lijekovima

Occupational exposure to antineoplastic drugs (ADs) handling and administration is one of the main risks in the healthcare sector. Dermal absorption represents the primary route of exposure to ADs. Personal preventive equipment, especially medical gloves, is crucial to safeguard the workers health in ADs handling; thus, chemicals permeating through protective materials is an essential aspect to estimate and consider. Several studies on permeation through medical gloves reported that breakthrough time and permeation rate are the values that must be studied, observing that physical-chemical properties of drugs, PPE materials and thickness, and temperature are crucial features to estimate them. In the European Union, standardized permeation testing is not mandatory for gloves used in ADs manipulation, in contrast with the United States, that proposed stringent requirements in the American Society of Testing and Materials International standard D6978-05. This review would help identify the main characteristics of the best protective glove used by employees frequently exposed to ADs: the major aspects implicated in permeation, reported in the literature, are listed and discussed.Radna izloženost rukovanju i primjeni antineoplastičnih lijekova (AD) jedan je od glavnih rizika u zdravstvenom sektoru. Kožna apsorpcija predstavlja primarni put izlaganju AD-ima. Osobna preventivna oprema, posebno medicinske rukavice, presudna je za zaštitu zdravlja radnika u radu s AD-ima; prema tome, kemikalije koje prodiru kroz zaštitne materijale bitan su aspekt za procjenu i razmatranje. Nekoliko studija o prožimanju kroz medicinske rukavice izvijestilo je da su vrijeme proboja i brzina prodiranja vrijednosti koje se moraju proučavati, primjećujući da su fizičko-kemijska svojstva lijekova, OZO materijali i debljina i temperatura ključne značajke za njihovu procjenu. U Europskoj uniji, standardizirano ispitivanje prožimanja nije obvezno za rukavice koje se koriste u manipulaciji ADs, za razliku od Sjedinjenih Država koje su predložile stroge zahtjeve u međunarodnom standardu D6978-05 Američkog društva za ispitivanje i materijale. Ovaj pregled pomogao bi identificirati glavne karakteristike najbolje zaštitne rukavice koju koriste zaposlenici često izloženi AD-ima: glavni aspekti uključeni u prožimanje, priopćeni u literaturi, navedeni su i raspravljeni

Evaluation of rare earth doped silica sub-micrometric spheres as optically controlled temperature sensors

We report on the evaluation of rare earth (Er3þ, Eu3þ, and Tb3þ ions) SiO2 sub-micrometric spheres as potential optically controllable temperature sensors. Details about fabrication, optical manipulation and spectroscopic characterization of the sub-micrometric spheres are presented. The fluorescence properties of the micros-spheres in the biological range (25–60 C) have been systematically investigated. From this systematic study, the thermal resolution potentially achieved in each case has been determined and compared to previous works

Years of life that could be saved from prevention of hepatocellular carcinoma

BACKGROUND: Hepatocellular carcinoma (HCC) causes premature death and loss of life expectancy worldwide. Its primary and secondary prevention can result in a significant number of years of life saved. AIM: To assess how many years of life are lost after HCC diagnosis. METHODS: Data from 5346 patients with first HCC diagnosis were used to estimate lifespan and number of years of life lost after tumour onset, using a semi-parametric extrapolation having as reference an age-, sex- and year-of-onset-matched population derived from national life tables. RESULTS: Between 1986 and 2014, HCC lead to an average of 11.5 years-of-life lost for each patient. The youngest age-quartile group (18-61 years) had the highest number of years-of-life lost, representing approximately 41% of the overall benefit obtainable from prevention. Advancements in HCC management have progressively reduced the number of years-of-life lost from 12.6 years in 1986-1999, to 10.7 in 2000-2006 and 7.4 years in 2007-2014. Currently, an HCC diagnosis when a single tumour <2 cm results in 3.7 years-of-life lost while the diagnosis when a single tumour 65 2 cm or 2/3 nodules still within the Milan criteria, results in 5.0 years-of-life lost, representing the loss of only approximately 5.5% and 7.2%, respectively, of the entire lifespan from birth. CONCLUSIONS: Hepatocellular carcinoma occurrence results in the loss of a considerable number of years-of-life, especially for younger patients. In recent years, the increased possibility of effectively treating this tumour has improved life expectancy, thus reducing years-of-life lost