1,178 research outputs found
LIPIcs, Volume 251, ITCS 2023, Complete Volume
LIPIcs, Volume 251, ITCS 2023, Complete Volum
Investigating the learning potential of the Second Quantum Revolution: development of an approach for secondary school students
In recent years we have witnessed important changes: the Second Quantum Revolution is in the spotlight of many countries, and it is creating a new generation of technologies.
To unlock the potential of the Second Quantum Revolution, several countries have launched strategic plans and research programs that finance and set the pace of research and development of these new technologies (like the Quantum Flagship, the National Quantum Initiative Act and so on).
The increasing pace of technological changes is also challenging science education and institutional systems, requiring them to help to prepare new generations of experts.
This work is placed within physics education research and contributes to the challenge by developing an approach and a course about the Second Quantum Revolution. The aims are to promote quantum literacy and, in particular, to value from a cultural and educational perspective the Second Revolution.
The dissertation is articulated in two parts. In the first, we unpack the Second Quantum Revolution from a cultural perspective and shed light on the main revolutionary aspects that are elevated to the rank of principles implemented in the design of a course for secondary school students, prospective and in-service teachers. The design process and the educational reconstruction of the activities are presented as well as the results of a pilot study conducted to investigate the impact of the approach on students' understanding and to gather feedback to refine and improve the instructional materials.
The second part consists of the exploration of the Second Quantum Revolution as a context to introduce some basic concepts of quantum physics. We present the results of an implementation with secondary school students to investigate if and to what extent external representations could play any role to promote students’ understanding and acceptance of quantum physics as a personal reliable description of the world
PELTA -- Shielding Multiparty-FHE against Malicious Adversaries
Multiparty fully homomorphic encryption (MFHE) schemes enable multiple parties to efficiently compute functions on their sensitive data while retaining confidentiality. However, existing MFHE schemes guarantee data confidentiality and the correctness of the computation result only against honest-but-curious adversaries. In this work, we provide the first practical construction that enables the verification of MFHE operations in zero-knowledge, protecting MFHE from malicious adversaries. Our solution relies on a combination of lattice-based commitment schemes and proof systems which we adapt to support both modern FHE schemes and their implementation optimizations. We implement our construction in PELTA. Our experimental evaluation shows that PELTA is one to two orders of magnitude faster than existing techniques in the literature
Foundations of Data Availability Sampling
Towards building more scalable blockchains, an approach known as data availability sampling (DAS) has emerged over the past few years.
Even large blockchains like Ethereum are planning to eventually deploy DAS to improve their scalability.
In a nutshell, DAS allows the participants of a network to ensure the full availability of some data without any one participant downloading it entirely.
Despite the significant practical interest that DAS has received, there are currently no formal definitions for this primitive, no security notions, and no security proofs for any candidate constructions.
For a cryptographic primitive that may end up being widely deployed in large real-world systems, this is a rather unsatisfactory state of affairs.
In this work, we initiate a cryptographic study of data availability sampling.
To this end, we define data availability sampling precisely as a clean cryptographic primitive.
Then, we show how data availability sampling relates to erasure codes.
We do so by defining a new type of commitment schemes which naturally generalizes vector commitments and polynomial commitments.
Using our framework, we analyze existing constructions and prove them secure.
In addition, we give new constructions which are based on weaker assumptions, computationally more efficient, and do not rely on a trusted setup, at the cost of slightly larger communication complexity.
Finally, we evaluate the trade-offs of the different constructions
That’s not my signature! Fail-stop signatures for a post-quantum world
The Snowden\u27s revelations kick-started a community-wide effort to develop cryptographic tools against mass surveillance.
In this work, we propose to add another primitive to that toolbox: Fail-Stop Signatures (FSS) [EC\u2789].
FSS are digital signatures enhanced with a forgery-detection mechanism that can protect a PPT signer from more powerful attackers.
Despite the fascinating concept, research in this area stalled after the \u2790s. However, the ongoing transition to post-quantum cryptography, with its hiccups due to the novelty of underlying assumptions, has become the perfect use case for FSS.
This paper aims to reboot research on FSS with practical use in mind: Our framework for FSS includes ``fine-grained\u27\u27 security definitions (that assume a powerful, but bounded adversary e.g: can break -bit of security, but not -bit).
As an application, we show new FSS constructions for the post-quantum setting.
We show that FSS are equivalent to standard, provably secure digital signatures that do not require rewinding or programming random oracles, and that this implies lattice-based FSS.
Our main construction is an FSS version of SPHINCS, which required building FSS versions of all its building blocks: WOTS, XMSS, and FORS.
In the process, we identify and provide generic solutions for two fundamental issues arising when deriving a large number of private keys from a single seed, and when building FSS for Hash-and-Sign-based signatures
Breaking the Consensus Bound: Asynchronous Dynamic Proactive Secret Sharing under Honest Majority
A proactive secret sharing scheme (PSS), expressed in the dynamic-membership setting, enables a committee of n holders of secret-shares, dubbed as players, to securely hand-over new shares of the same secret to a new committee. We dub such a sub-protocol as a Refresh. All existing PSS under an honest majority, require the use of a broadcast (BC) in each refresh. BC is costly to implement, and its security relies on timing assumptions on the network. So the privacy of the secret and/or its guaranteed delivery, either depend on network assumptions, or, on the reliability of a public ledger.
By contrast, PSS over asynchronous channels do not have these constraints. However, all of them (but one, with exponential complexity) use asynchronous verifiable secret sharing (AVSS) and consensus (MVBA and/or ACS), which are impossible under asynchrony beyond t<n/3 corruptions, whatever the setup.
We present a PSS, named asynchronous-proactive secret sharing (APSS), which is the first PSS under honest majority with guaranteed output delivery in a completely asynchronous network. More generally, APSS allows any flexible threshold , such that privacy and correctness are guaranteed up to t corruptions, and liveness as soon as players behave honestly.
Correctness can be lifted to any number of corruptions, provided a linearly homomorphic commitment scheme.
Moreover, each refresh completes at the record speed of , where is the actual message delivery delay.
APSS demonstrates that proactive refreshes are possible as long as players of the initial committee only, have a common view on a set of (publicly committed or encrypted) shares.
Despite not providing consensus on a unique set of shares, APSS surprisingly enables the opening of any linear map over secrets { non-interactively, without consensus }. This, in turn, applies to threshold signing, decryption and randomness generation.
APSS can also be directly integrated into the asynchronous Schnorr threshold signing scheme Roast [CCS\u2722].
Of independent interest, we:
- provide the first UC formalization (and proof) of proactive AVSS, furthermore for arbitrary thresholds;
- provide additional mechanisms enabling players of a committee to start a refresh then erase their old shares, synchronously up to from each other;
- improve by 50x the verification speed of the NIZKs of encrypted re-sharing of [Cascudo et al, Asiacrypt\u2722], by using novel optimizations of batch Schnorr proofs of knowledge.
We demonstrate efficiency of APSS with an implementation which uses this optimization as baseline
2017 GREAT Day Program
SUNY Geneseo’s Eleventh Annual GREAT Day.https://knightscholar.geneseo.edu/program-2007/1011/thumbnail.jp
- …