39 research outputs found
A First Appraisal of Cryptographic Mechanisms for the SelectiveDisclosure of Verifiable Credentials
No full textVerifiable credentials are a digital analogue of physical credentials. Their authenticity and integrity are protected by means of cryptographic techniques, and they can be presented to verifiers to prove claims about the holder of the credential itself. One way to preserve privacy during presentation consists in selectively disclosing the attributes in a credential. In this paper we present the most widespread cryptographic mechanisms used to enable selective disclosure of attributes, describing their structure and comparing them in terms of performance, size of the associated verifiable presentations, and the ability to produce predicate proofs and unlinkable presentations
On cryptographic mechanisms for the selective disclosure of verifiable credentials
No full textVerifiable credentials are a digital analogue of physical credentials. Their authenticity and integrity are protected by means of cryptographic techniques, and they can be presented to verifiers to reveal attributes or even predicates about the attributes included in the credential. One way to preserve privacy during presentation consists in selectively disclosing the attributes in a credential. In this paper we present the most widespread cryptographic mechanisms used to enable selective disclosure of attributes identifying two categories: the ones based on hiding commitments - e.g., mdl ISO/IEC 18013-5 - and the ones based on non-interactive zero-knowledge proofs - e.g., BBS signatures. We also include a description of the cryptographic primitives used to design such cryptographic mechanisms.
We describe the design of the cryptographic mechanisms and compare them by performing an analysis on their standard maturity in terms of standardization, cryptographic agility and quantum safety, then we compare the features that they support with main focus on the unlinkability of presentations, the ability to create predicate proofs and support for threshold credential issuance.
Finally we perform an experimental evaluation based on the Rust open source implementations that we have considered most relevant. In particular we evaluate the size of credentials and presentations built using different cryptographic mechanisms and the time needed to generate and verify them. We also highlight some trade-offs that must be considered in the instantiation of the cryptographic mechanisms
Codici Reed-Solomon: Un approccio alla decodifica
No full textIl primo obiettivo di questa tesi è quello di presentare i codici di correzione dell’errore detti di Reed-Solomon. L'idea di base dei codici di correzione dell'errore è quella di aggiungere una certa quantità di dati ad un messaggio che intendiamo spedire tramite un canale disturbato. Lo scopo di tale ridondanza è quello, tramite la decodifica del messaggio, di identificare determinati errori che potrebbero verificarsi nella trasmissione. Bisogna però limitare i dati in eccesso in modo da non influenzare troppo il costo di trasmissione. I codici Reed-Solomon sono particolarmente efficienti a tale scopo, tuttavia proporre un algoritmo in grado di decodificarli può risultare ostico.
Il secondo obiettivo di questa tesi è quello di analizzare un algoritmo di decodifica e di dimostrarne la validità tramite l'utilizzo di polinomi interpolanti
Aro minor, Cinoglosa, Staecha foli ferrati
No full text1. Nome scientifico: Arum maculatum (L.) DC.
(Araceae)
Nome attuale: Gigaro scuro, Pan di serpe
2. Nome scientifico: Anchusa sp. L.
(Boraginaceae)
Nome attuale: Buglossa
3. Nome scientifico: Lavandula dentata L.
(Lamiaceae, Labiatae)
Nome attuale: Lavanda dentata, Spigo nard
Ranitidine in long-term duodenal ulcer treatment: A multicentre trial
No full textAn endoscopically controlled clinical trial on maintenance Ranitidine treatment of scarred duodenal ulcer was carried out in 78 patients, randomly allocated to either 150 mg Ranitidine at night or low-dose antacid when necessary in a 1-year follow-up study. The maintenance Ranitidine regime prevented ulcer relapse in 23 of 31 cases (74.2%), without any significant adverse reaction. In the control group, the relapse was prevented in 12 of 30 cases (40%); the difference was found to be statistically significant
A seismic analysis for masonry constructions: The different schematization methods of masonry walls
No full textVISIR: technological infrastructure of an operational service for safe and efficient navigation in the Mediterranean Sea
No full textVISIR
(discoVerIng Safe and effIcient Routes) is an operational decision support
system (DSS) for optimal ship routing designed and implemented in the frame
of the TESSA (TEchnology for Situational Sea Awareness) project. The system
is aimed to increase safety and efficiency of navigation through the use of
forecast environmental fields and route optimization. VISIR can be accessed
through a web interface (www.visir-nav.com) and mobile applications for
both iOS and Android devices. This paper focuses on the technological
infrastructure developed for operating VISIR as a DSS. Its main components
are described, the performance of the operational system is assessed through
experimental measurements, and a few case studies are presented
Un cielo scuro di stelle – Terra d’Oblio, (introduzione, traduzione dall'arabo, note e cura)
No full textHere the author leaves the task of recalling the Iraqi history to the writing; in fact he brings to mind two chronological tragic moments: the Karbala tragedy of 680 d.c. when the Shia were awfully massacred, and the 1991 revolt when again the Shia members were dreadfully slaughtered by Saddam.
As almost all his texts, this one too deals with the trauma of exile, loss of home and identity. Both home and exile are stripped of any mystique – and yet the author, by his own admission, can still not overcome either the sense of nostalgia or otherness he feels as a result of his experiences of exile. He writes to exist, to preserve the memory and to support the burden of déracinement
