11,603 research outputs found
Rede uitgesproken op 17 september 1956 ter gelegenheid van de erepromotie van Dr. Th. von Karman door de promotor Dr. C.B. Biezeno
No full textRede uitgesproken door prof. C.B. Biezeno ter gelegenheid van de erepromotie aan de TH Delft van dr. Theodore von Karman.Precision and Microsystems EngineeringMechanical, Maritime and Materials Engineerin
Prof. Th. W. Adorno and the author Hans Erich Nossack.
No full textProf. Th. W. Adorno and the author Hans Erich Nossack at a reception of Insel Verlag, Buchmesse Frankfurt 1966LB
Author, publisher and bookseller : a tripartite synergy in Nigerian book industry
No full textThis work is about the roles of Author, Publisher and Bookseller in Book development in
Nigeria. The paper started by delving into the history of Book Publishing in Nigeria after
which it proceeded by defining who an author, a publisher, and a bookseller is and
expatiated on the indispensable roles of these key actors in Nigerian Book Industry and in
the emerging Information Society. Furthermore, the various constraints to book
development were identified while the paper advised on how the Book Industry can be
further promoted in Nigeria. However, the paper concluded and made recommendations
on how the Book sector can help in enhancing scholarship in the country
Dissipative Range Scaling of Higher Order Structure Functions for Velocity and Passive Scalars
No full textDifferently to Kolmogorov's second similarity hypothesis, we find that the 2n-th order velocity and scalar structure functions scale with n-th order moment of the energy dissipation and the scalar dissipation, respectively. The origins of this scaling are analyzed by the transport equations of the fourth order velocity and scalar increment moments and by direct numerical simulations
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
"Faust" / by Ravenswood author of Th Opera "Rudolph", The Cantata "Arno, or The Syren of of [!] the Wild-See", The Cantata "Roselfa", etc.
No full text"FAUST" / BY RAVENSWOOD AUTHOR OF TH OPERA "RUDOLPH", THE CANTATA "ARNO, OR THE SYREN OF OF [!] THE WILD-SEE", THE CANTATA "ROSELFA", ETC.
"Faust" / by Ravenswood author of Th Opera "Rudolph", The Cantata "Arno, or The Syren of of [!] the Wild-See", The Cantata "Roselfa", etc. (1)
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Opening van vier nieuwe laboratoria van de Afdeling der Werktuigbouwkunde van de Technische Hogeschool Delft
No full textSamenvatting van de toespraak door Prof.ir, R. van Hasselt bij de officiele opening van vier nieuwe laboratoriavan de Afdeling der Werktuigbouwkunde Boon, E.F. en Boot, J.: het Laboratorium voor Chemische Werktuigen Vahl, L.: het Laboratorium voor Koudetechniek Van Eldik Thieme, H.C.A.: het Laboratorium voor Voertuigtechniek Blok, H.: het Laboratorium voor WerktuigonderdelenWerktuigbouwkundeMechanical, Maritime and Materials Engineerin
Provenance of legacy-compatible data in the decentralized world and its applications
No full textA novel identity management concept known as decentralized identity (or self-sovereign identity) has drawn significant interest and extensive development within both academic and industrial circles. Decentralized oracles empower users to demonstrate the origin of data accessed through TLS from a specific website and verify statements concerning that data. This system operates without the reliance on trusted hardware or requiring modifications on the server side. In DECO (CCS 2020), the first decentralized oracle within TLS 1.2 was introduced. It also investigates the methodology of optionally proving statements about this data in a zero-knowledge setting, preserving the confidentiality of the data itself. Furthermore, a separate study proposed an attribute-based anonymous credential system incorporating a commitment scheme (ASIACRYPT 2020), introducing show proofs to verify a set of attributes in a credential to verifiers without disclosing attribute specifics. Building upon these research findings, this thesis presents a series of optimizations and expansions aimed at advancing self-sovereign identity solutions.
First, we present DIDO and DIDO+ (decentralized identification oracle), which expands DECO to TLS 1.3. In DIDO, we address several unresolved challenges, encompassing the incorporation of X25519 key exchange, the creation of a round-optimal three-party key exchange, the structuring of a 2PC system for TLS 1.3 key scheduling, and the optimization of circuit design for 2PC protocols.
Furthermore, we expand upon DIDO to create DIDO+, which introduces a protocol named selective disclosure. This protocol facilitates the extraction of particular plaintext substrings from websites, enhancing the functionality and flexibility of the system.
Our implementation is verified against real-world websites, and a security proof is furnished to validate its integrity.
Next, we introduce DEVS (decentralized verification service), the first generic decentralized verification service built on a decentralized oracle. DEVS enhances the traditional single-verifier oracle by incorporating a multi-verifier mechanism. Our aim is to streamline the protocol for reduced communication and computation costs while enabling reusable proofs and maintaining security. DEVS comprises three key components: a reconstructed decentralized oracle to bolster data trust, secure storage for share retention, and a verification process tailored to the needs of verifiers and authorities. Considering 10 verifiers, the reconstruction reduces the running time (approximately 89.1% or 89.6%) in WAN settings and communication bandwidth (approximately 89.1% or 87.8%) of TLS 1.2 or 1.3, it provides a significant improvement when working with multiple verifiers.
Lastly, we introduce a unified attribute-based anonymous credential system where users consistently receive credentials in a standardized format from the issuer. This system allows users to opt for efficient multi-use or single-use show proofs, offering a more user-centric perspective compared to current schemes. Technically, we suggest an interactive method for the credential issuance protocol utilizing two-party computation with additive homomorphic encryption. This approach maintains crucial security features such as impersonation resilience, anonymity, and unlinkability. In addition to the interactive protocol, we develop show proofs tailored for efficient single-use credentials that uphold user anonymity throughout the process.published_or_final_versionComputer ScienceDoctoralDoctor of Philosoph
Efficient private set intersection
No full textPrivate set intersection (PSI) is a special kind of secure computation. It enables n parties to securely get the intersection of their sets. In this thesis, we first propose an oblivious key-value store (OKVS) Multi-PGBF, which is a data structure that can obliviously encode key-value pairs. Multi-PGBF has many advantages compared with existing OKVSs. For example, compared with PaXoS (Eurocrypt’20) and 3H-GCT (Crypto’21), it has faster encoding and decoding efficiency by using smaller storage. Then we combine Multi-PGBF with a cryptographic primitive called Vector Oblivious Linear function Evaluation (VOLE) to design our first two-party unfair PSI protocol that can achieve the lowest communication costs and computation costs. We also combine cuckoo hashing with VOLE to design another two-party unfair PSI protocol. As a result, it can run comparably as fast as our first unfair PSI protocol in the LAN network setting.
In unfair PSI, only one party gets the intersection while the other parties learn nothing. However, there are needs in real-world applications where two parties both want to know the intersection. Therefore, we propose the first two-party fair PSI protocol by combining our two-party unfair PSI protocol and PSI-Cardinality (PSI-CA) protocol. Two-party unfair PSI-CA is a variant of PSI, in which one party knows the intersection cardinality rather than the intersection in PSI. We propose a computationally friendly two-party unfair PSI-CA protocol.
There is also a kind of PSI(-CA) called unbalanced PSI(-CA), in which one party has a set with a size much smaller than the other party. The focus of unbalanced PSI(-CA) protocols is the low communication cost. We propose the most efficient unbalanced PSI-CA protocols with the lowest communication complexity O(ny log(nx)), where ny and nx are respectively the small set size and large set size. Our unbalanced PSI-CA protocols can be easily modified into unbalanced PSI protocols. Compared with the state-of-the-art unbalanced PSI work (Cong et al., CCS’21), one of our unbalanced PSI protocols can save 42%~59% communication costs and accelerate the running time. We apply one of our lightweight unbalanced PSI-CA protocols to design a privacy-preserving contact tracing system, which shows obvious advantages against related designs.
We also design a multi-party unfair PSI protocol by utilizing OKVS and a cryptographic primitive called oblivious pseudorandom function. It is the first ring-based multi-party PSI protocol that can balance the communication and computation costs between the parties. We also design a star-based multi-party PSI protocol. As a result, our multi-party protocols are respectively 3.69%~51.15% and 5.24%~105.84% cheaper than the state-of-the-art counterparts KMPRT (CCS’17) and CDGOSS (CCS’21) in the total communication costs.published_or_final_versionComputer ScienceDoctoralDoctor of Philosoph
Provable Security:13th International Conference, ProvSec 2019, Cairns, QLD, Australia, October 1–4, 2019, Proceedings
No full textThis book constitutes the refereed proceedings of the 13th International Conference on Provable Security, ProvSec 2019, held in Cairns, QLD, Australia, in October 2019. The 18 full and 6 short papers presented were carefully reviewed and selected from 51 submissions. The papers focus on provable security as an essential tool for analyzing security of modern cryptographic primitives, including a special theme on 'Practical Security.
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