mRLWE-CP-ABE: A revocable CP-ABE for post-quantum cryptography

We address the problem of user fast revocation in the lattice-based Ciphertext Policy Attribute-Based Encryption (CP-ABE) by extending the scheme originally introduced by Zhang and Zhang [Zhang J, Zhang Z. A ciphertext policy attribute-based encryption scheme without pairings. In: International Conference on Information Security and Cryptology. Springer; 2011. p. 324-40. doi: https://doi.org/10.1007/978-3-642-34704-7_23.]. While a lot of work exists on the construction of revocable schemes for CP-ABE based on pairings, works based on lattices are not so common, and - to the best of our knowledge - we introduce the first server-aided revocation scheme in a lattice-based CP-ABE scheme, hence being embedded in a post-quantum secure environment. In particular, we rely on semi-trusted "mediators" to provide a multi-step decryption capable of handling mediation without re-encryption. We comment on the scheme and its application, and we provide performance experiments on a prototype implementation in the Attribute-Based Encryption spin-off library of Palisade to evaluate the overhead compared with the original scheme

Ten years of cube attacks

In 2009, Dinur and Shamir proposed the cube attack, an algebraic cryptanalysis technique that only requires black box access to a target cipher. Since then, this attack has received both many criticisms and endorsements from crypto community; this work aims at revising and collecting the many attacks that have been proposed starting from it. We categorise all of these attacks in five classes; for each class, we provide a brief summary description along with the state-of-the-art references and the most recent cryptanalysis results. Furthermore, we extend and refine the new notation we proposed in 2021 and we use it to provide a consistent definition for each attack family. Finally, in the appendix, we provide an in-depth description of the kite attack framework, a cipher independent tool we firstly proposed in 2018 that implements the kite attack on GPUs. To prove its effectiveness, we use Mickey2.0 as a use case, showing how to embed it in the framework

Onion under Microscope: An in-depth analysis of the Tor network

Tor is an anonymity network that allows offering and accessing various kinds of resources, known as hidden services, while guaranteeing sender and receiver anonymity. The Tor web is the set of web resources that exist on the Tor network, and Tor websites are part of the so-called dark web. Recent research works have evaluated Tor security, evolution over time, and thematic organization. Nevertheless, few information are available about the structure of the graph defined by the network of Tor websites. The limited number of Tor entry points that can be used to crawl the network renders the study of this graph far from being simple. In this paper we aim at better characterizing the Tor Web by analyzing three crawling datasets collected over a five-month time frame. On the one hand, we extensively study the global properties of the Tor Web, considering two different graph representations and verifying the impact of Tor's renowned volatility. We present an in depth investigation of the key features of the Tor Web graph showing what makes it different from the surface Web graph. On the other hand, we assess the relationship between contents and structural features. We analyse the local properties of the Tor Web to better characterize the role different services play in the network and to understand to which extent topological features are related to the contents of a service

Inferring urban social networks from publicly available data

The emergence of social networks and the definition of suitable generative models for synthetic yet realistic social graphs are widely studied problems in the literature. By not being tied to any real data, random graph models cannot capture all the subtleties of real networks and are inadequate for many practical contexts -- including areas of research, such as computational epidemiology, which are recently high on the agenda. At the same time, the so-called contact networks describe interactions, rather than relationships, and are strongly dependent on the application and on the size and quality of the sample data used to infer them. To fill the gap between these two approaches, we present a data-driven model for urban social networks, implemented and released as open source software. Given a territory of interest, and only based on widely available aggregated demographic and social-mixing data, we construct an age-stratified and geo-referenced synthetic population whose individuals are connected by "strong ties" of two types: intra-household (e.g., kinship) or friendship. While household links are entirely data-driven, we propose a parametric probabilistic model for friendship, based on the assumption that distances and age differences play a role, and that not all individuals are equally sociable. The demographic and geographic factors governing the structure of the obtained network, under different configurations, are thoroughly studied through extensive simulations focused on three Italian cities of different size

Postfordismo e trasformazione urbana.Casi di recupero dei vuoti industriali e indicazioni per le politiche nel territorio torinese

Il volume sulle aree dismesse e la trasformazione urbana promosso dalla Direzione Competitività della Regione Piemonte e dall'ente strumentale di ricerca economica e sociale, IRES Piemonte, racchiude contributi su esperienze di recupero dei vuoti urbani industriali e casi rilevanti della trasformazione urbana che hanno interessato Torino e la sua area metropolitana.- Prefazione #7- Introduzione #9- 1. Le ristrutturazioni industriali e il territorio: crisi, declino,metamorfosi? #33- 2. Scoprire i vuoti industriali: analisi e riflessioni a partire da censimenti e mappature di aree industriali dismesse a Torino #51- 3. Le aree dismesse nella riqualificazione e nella rigenerazione urbana a Torino (1990-2015) #113- 4. La trasformazione urbana tra grandi interventi e architetture “ordinarie”. #147- 5. Due esperienze di rigenerazione urbana sul territorio torinese:il Comitato Parco Dora sulla Spina 3 e il Comitato Urban in Barriera di Milano, a Torino #169- 6. Da cittadella industriale a Spina 3: una riconversione incompiuta #193- 7. Ex Diatto - Ex Westinghouse, due casi emblematici per le politiche di rivitalizzazione delle aree industriali torinesi #211- 8. Mirafiori. Dalla componentistica allo yogurt: storia di un progetto di re-industrializzazione #229- 9. Area OSI OVEST-NORD: Toolbox Coworking! #247- 10. Abilitare il territorio metropolitano alla rigenerazione e ad un nuovo sviluppo. Il caso di None, dall'industria subita all'industria inseguita #275- 11. Le ex-Acciaierie Mandelli di Collegno: la storia di una fabbrica,l'attualità del dibattito urbanistico. #301- 12. I programmi territoriali quale motore di rigenerazione urbana e di politiche di contenimento del consumo di suolo nel comune di Settimo Torinese #323- 13. La Regione Piemonte e la sfida del contenimento del consumo di suolo e del riutilizzo delle aree dismesse #353- 14. Torino, la nascita della città postindustriale: quale bilancio? #365- 15. Valutare i rischi della riqualificazione urbanistica e ambientale delle aree industriali dismesse #381- 16. Le aree industriali dismesse e il loro impatto sulla salute: il ruolo dei cittadini e delle amministrazioni locali nell'identificazione dei problemi e delle possibili soluzioni. #405- 17. I giovani e la città che cambia. Nuovi passi e nuovi sguardi sulle tracce di un passato industriale #427- Elenco degli autori e delle autrici #44

mRLWE-CP-ABE: A revocable CP-ABE for post-quantum cryptography

We address the problem of user fast revocation in the lattice-based Ciphertext Policy Attribute-Based Encryption (CP-ABE) by extending the scheme originally introduced by Zhang and Zhang [Zhang J, Zhang Z. A ciphertext policy attribute-based encryption scheme without pairings. In: International Conference on Information Security and Cryptology. Springer; 2011. p. 324–40. doi: https://doi.org/10.1007/978-3-642-34704-7_23.]. While a lot of work exists on the construction of revocable schemes for CP-ABE based on pairings, works based on lattices are not so common, and – to the best of our knowledge – we introduce the first server-aided revocation scheme in a lattice-based CP-ABE scheme, hence being embedded in a post-quantum secure environment. In particular, we rely on semi-trusted “mediators” to provide a multi-step decryption capable of handling mediation without re-encryption. We comment on the scheme and its application, and we provide performance experiments on a prototype implementation in the Attribute-Based Encryption spin-off library of Palisade to evaluate the overhead compared with the original scheme

mRLWE_{\text{LWE}}-CP-ABE a revocable CP-ABE for Post-Quantum Cryptography

We address the problem of user fast revocation in the lattice based CP-ABE by extending the scheme originally introduced in [A ciphertext policy attribute-based encryption scheme without pairings. J. Zhang, Z. Zhang - ICISC 2011]. While a lot of work exists on the construction of revocable schemes for CP-ABE based on pairings, works based on lattices are not so common, and – to the best of our knowledge – we introduce the first server-aided revocation scheme in a lattice based CP-ABE scheme, hence providing post-quantum safety. In particular, we rely on semi-trusted mediators to provide a multi-step decryption capable of handling mediation without re-encryption. We comment on the scheme and its application and we provide performance experiments on a prototype implementation in the ABE spin-off library of Palisade to evaluate the overhead compared with the original scheme