Potential of EUMETSAT MTG-IRS hyperspectral sounder for improving nowcasting and very short range forecast atmospheric models

Obiettivo delle attività di ricerca descritte in questa tesi è lo studio dell’utilizzo dei dati iperspettrali IR per la diagnosi dell’instabilità atmosferica ed il rilevamento anticipato di sistemi convettivi. Lo studio è stato condotto nell’ambito del progetto MTG-IRS Near Real Time, concepito e coordinato da EUMETSAT per potenziare la preparazione degli utenti sulle potenzialità dello strumento IRS a supporto della meteorologia ed in particolare delle attività di previsioni a brevissima scadenza. In dettaglio, i prodotti iperspettrali di levello 2 di IRS, generati a partire da dati reali di IASI e CrIS e distribuiti da EUMETSAT, sono stati processati in quasi tempo reale insieme a dati ausiliari geograficamente co-localizzati ed indipendenti al fine di valutare la correlazione tra il segnale (cioè il contenuto informativo dei prodotti di livello 2) ed il fenomeno meteorologico (l’instabilità convettiva). Lo studio comprende anche il riprocessamento di una serie di casi di studio significativi sull’Italia. I risultati della ricerca mostrano che lo sfruttamento dei dati iperspettrali nel settore delle previsioni a brevissima scadenza è in grado di potenziare la capacità e la prontezza a livello utente dei moderni Servizi Meteorologici operativi per quanto riguarda il rilevamento in anticipo dei fenomeni intensi.In this thesis the research activities aiming at the investigation on the use of hyperspectral IR data for the diagnosis of atmospheric instability and the early detection of convective systems are shown. The study was carried out in the framework of MTG-IRS Near Real Time Demonstration Project, conceived and leaded by EUMETSAT to enhance the user awareness on the potential of the IRS instrument in support to the meteorology and in particular to the nowcasting activities. In detail, the proxy IRS hyperspectral level 2 products, generated from real IASI and CrIS data and distributed by EUMETSAT, were processed in near real time together with auxiliary colocated and independent datasets to assess the correlation between the signal (i.e. the information content of level 2 products) and the weather phenomenon (convective instability). The reprocess of a set of significant case studies over Italy was also included in the study. Research results show that the exploitation of hyperspectral data in the field of nowcasting applications could enhance the capacity and user-readiness of modern, operational Meteorological Services with respect to the early detection of severe weather

SoK: Delegation and Revocation, the Missing Links in the Web's Chain of Trust

The ability to quickly revoke a compromised key is critical to the security of any public-key infrastructure. Regrettably, most traditional certificate revocation schemes suffer from latency, availability, or privacy problems. These problems are exacerbated by the lack of a native delegation mechanism in TLS, which increasingly leads domain owners to engage in dangerous practices such as sharing their private keys with third parties. We analyze solutions that address the long-standing delegation and revocation shortcomings of the web PKI, with a focus on approaches that directly affect the chain of trust (i.e., the X.509 certification path). For this purpose, we propose a 19-criteria framework for characterizing revocation and delegation schemes. We also show that combining short-lived delegated credentials or proxy certificates with an appropriate revocation system would solve several pressing problems.Comment: IEEE European Symposium on Security and Privacy (EuroS&P) 202

Intelligent Computing for Big Data

Recent advances in artificial intelligence have the potential to further develop current big data research. The Special Issue on ‘Intelligent Computing for Big Data’ highlighted a number of recent studies related to the use of intelligent computing techniques in the processing of big data for text mining, autism diagnosis, behaviour recognition, and blockchain-based storage

Secure Proxy Signature Schemes for Delegation of Signing Rights

A proxy signature scheme permits an entity to delegate its signing rights to another entity. These schemes have been suggested for use in numerous applications, particularly in distributed computing. But to date, no proxy signature schemes with guaranteed security have been proposed; no precise definitions or proofs of security have been provided for such schemes. In this paper, we formalize a notion of security for proxy signature schemes and present provably-secure schemes. We analyze the security of the well-known delegation-by-certificate scheme and show that after some slight but important modifications, the resulting scheme is secure, assuming the underlying standard signature scheme is secure. We then show that employment of the recently introduced aggregate signature schemes permits bandwidth and computational savings. Finally, we analyze the proxy signature scheme of Kim, Park and Won, which offers important performance benefits. We propose modifications to this scheme that preserve its efficiency, and yield a proxy signature scheme that is provably secure in the random-oracle model, under the discrete-logarithm assumption