Reviewerly/exHarmony huggingface dataset:
Fractional Vehicle Ownership and Revenue Generation Through Blockchain Asset Tokenization

Abstract The automotive industry is on a continuous transition towards a more sustainable and integrated ecosystem influenced by the fast-paced adoption of Electrical Vehicles (EVs) and the developments of emerging technologies such as Automated Vehicles (AVs). The road transportation sector is also experimenting with the emergent decentralized blockchain technology in various ways ranging from supply chain transparency to insurance and tokenization. Some of the recent use cases are the use of Non-Fungible Tokens (NFTs), unique digital assets designed to be immutable, to certify ownership of a vehicle, the data history of it or just for fan base development. The current paper reviews the literature findings concerning the potential of Non-Fungible Tokens for the automotive industry and proposes a new car ownership and revenue generation model using the ERC-1155 token standard. Our proof-of-concept based on fractional vehicle ownership demonstrates the feasibility of such a model that allows for revenue distribution amongst the vehicle owners according to the percentile invested in the vehicle acquisition.
Rai-Choo! Evolving Blind Signatures to the Next Level

Blind signatures are a fundamental tool for privacy-preserving applications. Known constructions of concurrently secure blind signature schemes either are prohibitively inefficient or rely on non-standard assumptions, even in the random oracle model. A recent line of work (ASIACRYPT ‘21, CRYPTO ‘22) initiated the study of concretely efficient schemes based on well-understood assumptions in the random oracle model. However, these schemes still have several major drawbacks: 1) The signer is required to keep state; 2) The computation grows linearly with the number of signing interactions, making the schemes impractical; 3) The schemes require at least five moves of interaction. In this paper, we introduce a blind signature scheme that eliminates all of the above drawbacks at the same time. Namely, we show a round-optimal, concretely efficient, concurrently secure, and stateless blind signature scheme in which communication and computation are independent of the number of signing interactions. Our construction also naturally generalizes to the partially blind signature setting. Our scheme is based on the $$\textsf{CDH}$$ assumption in the asymmetric pairing setting and can be instantiated using a standard BLS curve. We obtain signature and communication sizes of 9 KB and 36 KB, respectively. To further improve the efficiency of our scheme, we show how to obtain a scheme with better amortized communication efficiency. Our approach batches the issuing of signatures for multiple messages.
Polynomial-Time Cryptanalysis of the Subspace Flooding Assumption for Post-quantum $$i\mathcal {O}$$

Indistinguishability Obfuscation $$(i\mathcal {O})$$ is a highly versatile primitive implying a myriad advanced cryptographic applications. Up until recently, the state of feasibility of $$i\mathcal {O}$$ was unclear, which changed with works (Jain-Lin-Sahai STOC 2021, Jain-Lin-Sahai Eurocrypt 2022) showing that $$i\mathcal {O}$$ can be finally based upon well-studied hardness assumptions. Unfortunately, one of these assumptions is broken in quantum polynomial time. Luckily, the line work of Brakerski et al. Eurocrypt 2020, Gay-Pass STOC 2021, Wichs-Wee Eurocrypt 2021, Brakerski et al. ePrint 2021, Devadas et al. TCC 2021 simultaneously created new pathways to construct $$i\mathcal {O}$$ with plausible post-quantum security from new assumptions, namely a new form of circular security of LWE in the presence of leakages. At the same time, effective cryptanalysis of this line of work has also begun to emerge (Hopkins et al. Crypto 2021). It is important to identify the simplest possible conjectures that yield post-quantum $$i\mathcal {O}$$ and can be understood through known cryptanalytic tools. In that spirit, and in light of the cryptanalysis of Hopkins et al., recently Devadas et al. gave an elegant construction of $$i\mathcal {O}$$ from a fully-specified and simple-to-state assumption along with a thorough initial cryptanalysis. Our work gives a polynomial-time distinguisher on their “final assumption” for their scheme. Our algorithm is extremely simple to describe: Solve a carefully designed linear system arising out of the assumption. The argument of correctness of our algorithm, however, is nontrivial. We also analyze the “T-sum” version of the same assumption described by Devadas et al. and under a reasonable conjecture rule out the assumption for any value of T that implies $$i\mathcal {O}$$ .
A New Framework for Quantum Oblivious Transfer

We present a new template for building oblivious transfer from quantum information that we call the "fixed basis" framework. Our framework departs from prior work (e.g., Crepeau and Kilian, FOCS'88) by fixing the correct choice of measurement basis used by each player, except for some hidden trap qubits that are intentionally measured in a conjugate basis. We instantiate this template in the quantum random oracle model (QROM) to obtain simple protocols that implement, with security against malicious adversaries: Along the way, we develop technical tools that may be of independent interest. We prove that natural functions like XOR enable seedless randomness extraction from certain quantum sources of entropy. We also use idealized (i.e. extractable and equivocal) bit commitments, which we obtain by proving security of simple and efficient constructions in the QROM.
Randomized Half-Ideal Cipher on Groups with Applications to UC (a)PAKE

An Ideal Cipher (IC) is a cipher where each key defines a random permutation on the domain. Ideal Cipher on a group has many attractive applications, e.g., the Encrypted Key Exchange (EKE) protocol for Password Authenticated Key Exchange (PAKE) [8], or asymmetric PAKE (aPAKE) [31, 33]. However, known constructions for IC on a group domain all have drawbacks, including key leakage from timing information [12], requiring 4 hash-onto-group operations if IC is an 8-round Feistel [22], and limiting the domain to half the group [9] or using variable-time encoding [39, 47] if IC is implemented via (quasi-) bijections from groups to bitstrings [33]. We propose an IC relaxation called a (Randomized) Half-Ideal Cipher (HIC), and we show that HIC on a group can be realized by a modified 2-round Feistel (m2F), at a cost of 1 hash-onto-group operation, which beats existing IC constructions in versatility and computational cost. HIC weakens IC properties by letting part of the ciphertext be non-random, but we exemplify that it can be used as a drop-in replacement for IC by showing that EKE [8] and aPAKE of [33] realize respectively UC PAKE and UC aPAKE even if they use HIC instead of IC. The m2F construction can also serve as IC domain extension, because m2F constructs HIC on domain D from an RO-indifferentiable hash onto D and an IC on $$2{\kappa }$$ -bit strings, for $${\kappa }$$ a security parameter. One application of such extender is a modular lattice-based UC PAKE using EKE instantiated with HIC and anonymous lattice-based KEM.
Half-Tree: Halving the Cost of Tree Expansion in COT and DPF

GGM tree is widely used in the design of correlated oblivious transfer (COT), subfield vector oblivious linear evaluation (sVOLE), distributed point function (DPF), and distributed comparison function (DCF). Often, the cost associated with GGM tree dominates the computation and communication of these protocols. In this paper, we propose a suite of optimizations that can reduce this cost by half. All protocols are provably secure in the random-permutation model and can be accelerated based on fixed-key AES-NI. We also improve the state-of-the-art schemes of puncturable pseudorandom function (PPRF), DPF, and DCF, which are of independent interest in dealer-available scenarios.
Revisiting BBS Signatures

BBS signatures were implicitly proposed by Boneh, Boyen, and Shacham (CRYPTO ’04) as part of their group signature scheme, and explicitly cast as stand-alone signatures by Camenisch and Lysyanskaya (CRYPTO ’04). A provably secure version, called BBS+, was then devised by Au, Susilo, and Mu (SCN ’06), and is currently the object of a standardization effort which has led to a recent RFC draft. BBS+ signatures are suitable for use within anonymous credential and DAA systems, as their algebraic structure enables efficient proofs of knowledge of message-signature pairs that support partial disclosure. BBS+ signatures consist of one group element and two scalars. As our first contribution, we prove that a variant of BBS+ producing shorter signatures, consisting only of one group element and one scalar, is also secure. The resulting scheme is essentially the original BBS proposal, which was lacking a proof of security. Here we show it satisfies, under the q-SDH assumption, the same provable security guarantees as BBS+. We also provide a complementary tight analysis in the algebraic group model, which heuristically justifies instantiations with potentially shorter signatures. Furthermore, we devise simplified and shorter zero-knowledge proofs of knowledge of a BBS message-signature pair that support partial disclosure of the message. Over the BLS12-381 curve, our proofs are 896 bits shorter than the prior proposal by Camenisch, Drijvers, and Lehmann (TRUST ’16), which is also adopted by the RFC draft. Finally, we show that BBS satisfies one-more unforgeability in the algebraic group model in a scenario, arising in the context of credentials, where the signer can be asked to sign arbitrary group elements, meant to be commitments, without seeing their openings.
Worst-Case Subexponential Attacks on PRGs of Constant Degree or Constant Locality

In this work, we will give new attacks on the pseudorandomness of algebraic pseudorandom number generators (PRGs) of polynomial stretch. Our algorithms apply to a broad class of PRGs and are in the case of general local PRGs faster than currently known attacks. At the same time, in contrast to most algebraic attacks, subexponential time and space bounds will be proven for our attacks without making any assumptions of the PRGs or assuming any further conjectures. Therefore, we yield in this text the first subexponential distinguishing attacks on PRGs from constant-degree polynomials and close current gaps in the subexponential cryptoanalysis of lightweight PRGs. Concretely, against PRGs $$F : \mathbb {Z}_q^{n} \rightarrow \mathbb {Z}_q^{m}$$ that are computed by polynomials of degree d over a field $$\mathbb {Z}_q$$ and have a stretch of $$m = n^{1+e}$$ we give an attack with space and time complexities $$n^{O(n^{1 - \frac{e}{d-1}})}$$ and noticeable advantage $$1 - {O(n^{1 - \frac{e}{d-1}}/{q})}$$ . If q lies in $$O(n^{1 - \frac{e}{d-1}})$$ , we give a second attack with the same space and time complexities whose advantage is at least $$q^{-O(n^{1 - \frac{e}{d-1}})}$$ . If F is of constant locality d and q is constant, we construct a third attack that has a space and time complexity of $$\exp (O(n^{1 - \frac{e'}{(q-1)d-1}}))$$ and noticeable advantage $$1-O(n^{-\frac{e'}{(q-1)d-1}})$$ for every constant $$e' < e$$ .
Black-Box Separations for Non-interactive Classical Commitments in a Quantum World

Commitments are fundamental in cryptography. In the classical world, commitments are equivalent to the existence of one-way functions. It is also known that the most desired form of commitments in terms of their round complexity, i.e., non-interactive commitments, cannot be built from one-way functions in a black-box way [Mahmoody-Pass, Crypto'12]. However, if one allows the parties to use quantum computation and communication, it is known that non-interactive commitments (to classical bits) are in fact possible [Koshiba-Odaira, Arxiv'11 and Bitansky-Brakerski, TCC'21]. We revisit the assumptions behind non-interactive commitments in a quantum world and study whether they can be achieved using quantum computation and classical communication based on a black-box use of one-way functions. We prove that doing so is impossible unless the Polynomial Compatibility Conjecture [Austrin et al. Crypto'22] is false. We further extend our impossibility to protocols with quantum decommitments. This complements the positive result of Bitansky and Brakerski [TCC'21], as they only required a classical decommitment message. Because non-interactive commitments can be based on injective one-way functions, assuming the Polynomial Compatibility Conjecture, we also obtain a black-box separation between one-way functions and injective one-way functions (e.g., one-way permutations) even when the construction and the security reductions are allowed to be quantum. This improves the separation of Cao and Xue [Theoretical Computer Science'21] in which they only allowed the security reduction to be quantum. At a technical level, we prove that sampling oracles at random from "sufficiently large" sets (of oracles) will make them one-way against polynomial quantum-query adversaries who also get arbitrary polynomial-size quantum advice about the oracle. This gives a natural generalization of the recent results of Hhan et al. [Asiacrypt'19] and Chung et al. [FOCS'20].
Weighted Oblivious RAM, with Applications to Searchable Symmetric Encryption

Existing Oblivious RAM protocols do not support the storage of data items of variable size in a non-trivial way. While the study of ORAM for items of variable size is of interest in and of itself, it is also motivated by the need for more performant and more secure Searchable Symmetric Encryption (SSE) schemes. In this article, we introduce the notion of weighted ORAM, which supports the storage of blocks of different sizes. We introduce a framework to build efficient weighted ORAM schemes, based on an underlying standard ORAM satisfying a certain suitability criterion. This criterion is fulfilled by various Tree ORAM schemes, including Simple ORAM and Path ORAM. We deduce several instantiations of weighted ORAM, with very little overhead compared to standard ORAM. As a direct application, we obtain efficient SSE constructions with attractive security properties.
Optimal Single-Server Private Information Retrieval

We construct a single-server pre-processing Private Information Retrieval (PIR) scheme with optimal bandwidth and server computation (up to poly-logarithmic factors), assuming hardness of the Learning With Errors (LWE) problem. Our scheme achieves amortized $$\widetilde{O}_{\lambda }(\sqrt{n})$$ server and client computation and $$\widetilde{O}_\lambda (1)$$ bandwidth per query, completes in a single roundtrip, and requires $$\widetilde{O}_\lambda (\sqrt{n})$$ client storage. In particular, we achieve a significant reduction in bandwidth over the state-of-the-art scheme by Corrigan-Gibbs, Henzinger, and Kogan (Eurocrypt’22): their scheme requires as much as $$\widetilde{O}_{\lambda }(\sqrt{n})$$ bandwidth per query, with comparable computational and storage overhead as ours.
A blockchain‐based privacy‐preserving advertising attribution architecture: Requirements, design, and a prototype implementation

Abstract In the era of digital marketing, advertisements have become an indispensable part. One of the central challenges is advertising attribution which explains the amount of contribution every publisher has with the conversions. However, through observation, we have found that current advertising platforms attribution, advertisers attribution, or third‐party platforms attribution all have the problems of trust, data leakage, and data forgery. To fill the gap, our work's main contribution is combining blockchain with advertising attribution to propose an architecture for improving the privacy‐preserving degree and amount. In the proposed architecture, publishers, and advertisers can store real‐time data on a blockchain. The attribution results are credible because blockchain is decentralized, tamper‐proof, and traceable. We combine privacy set intersection and zero‐knowledge proof technology to increase the privacy of flowing data. In addition, we describe a preliminary prototype in which publishers, advertisers, and advertising platforms can get the corresponding attribution details. To show its effectiveness, we analyze it from different perspectives, including communication cost, attribution accuracy, and time cost. The results show that our communication cost has significantly reduced compared to the recent studies.
"Defaulting to boilerplate answers, they didn't engage in a genuine conversation": Dimensions of Transparency Design in Creator Moderation

Transparency matters a lot to people who experience moderation on online platforms; much CSCW research has viewed offering explanations as one of the primary solutions to enhance moderation transparency. However, relatively little attention has been paid to unpacking what transparency entails in moderation design, especially for content creators. We interviewed 28 YouTubers to understand their moderation experiences and analyze the dimensions of moderation transparency. We identified four primary dimensions: participants desired the moderation system to present moderation decisions saliently, explain the decisions profoundly, afford communication with the users effectively, and offer repairment and learning opportunities. We discuss how these four dimensions are mutually constitutive and conditioned in the context of creator moderation, where the target of governance mechanisms extends beyond the content to creator careers. We then elaborate on how a dynamic, transparency perspective could value content creators' digital labor, how transparency design could support creators' learning, as well as implications for transparency design of other creator platforms.
"Oh yes! over-preparing for meetings is my jam :)": The Gendered Experiences of System Administrators

In the system and network administration domain, gender diversity remains a distant target. The experiences and perspectives of sysadmins who belong to marginalized genders (non cis-men) are not well understood beyond the fact that sysadmin work environments are generally not equitable. We address this knowledge gap in our study by focusing on the ways in which sysadmins from marginalized genders manage their work in men-dominated sysadmin work spaces and by understanding what an inclusive workplace would look like. Using a feminist research approach, we engaged with a group of 16 sysadmins who are not cis-men via six online focus groups. We found that managing the impact of gender identity in the sysadmin workplace means demonstrating excellence and going above and beyond in system administration tasks, and also requires performing additional care work not expected from cis men. Furthermore, our participants handle additional layers of work due to gender considerations and to actively find community in the workplace. We found that sysadmins manage by going above and beyond in their tasks, performing care work and doing extra layers of work because of gender considerations, and finding community in the workplace. To mitigate this additional workload, we recommend more care for care work. For future research, we recommend the use of feminist lenses when studying sysadmin work in order to provide more equitable solutions that ultimately contribute to improving system security by fostering a just workplace.
Constructing better prototype generators with 3D CNNs for few-shot text classification

Prototypical network is a key algorithm to solve few-shot problems. Previous prototypical network based methods average sentence embeddings of the same class to obtain corresponding class representation.1 However, this simple averaging fails to model the importance of word-level information to class representation effectively, thus limit the quality of prototype. In this work, we propose a 3D CNN2 based 3D Convolution Prototypical Network (3DCPN) which is mainly composed by two parts. To focus more effectively on the importance of word-level information from prototype perspective, firstly, we use a 3D CNN to process word embeddings of the same class. 3D CNNs are skilled at capturing semantic correlation from multiple objects. We utilize 3D CNNs to replace averaging to generate better class representation. Secondly, we construct a 2D semantic mining layer as the second part in 3DCPN to extract deep feature from query embeddings. Symmetric model structure is designed to ensure feature matching between class representation and query representation. After that, we obtain the similarity between the prototype representation and the query representation by a metric function. According to the calculated similarity matrix, we introduce a temperature coefficient based cross entropy as the objective function to optimize our model. Extensive experiments are conducted on four benchmarks. The results show that our model outperforms LaSAML by 1.88% and 2.28% on Banking77 under 10-way-5-shot and 15-way-5-shot respectively. For the other baselines, 3DCPN achieves average improvements of 4.90%, 4.53% and 8.81% on Clinc150, Hwu64 and Liu57 respectively.
Multi-Class Classification Prediction Model for Password Strength Based on Deep Learning

Various indexes are being used today to evaluate the strength of passwords.In these indexes, the strength of a password is evaluated to be high if it takes longer for an attacker to predict it.Therefore, using such an evaluation, there is a problem that a leaked password may reduce the reliability of the index by increasing vulnerability if an attacker attempts to attack using a leaked password.Hence, estimating the leaked frequency when considering strength is important for reducing vulnerability.This paper proposes a password strength evaluation model using deep learning-based multi-class classification, which solves the existing problem of leaked frequency not being considered during evaluation.Data preprocessing modeling is critical to improve the performance of this model.Additionally, since selecting and extracting feature values of preprocessing data is also important, a model that accurately estimates the degree of leakage through an evaluation method of existing indexes is proposed.To evaluate the performance of the proposed model, an experiment that compares the password leaked frequency stored in a database using a password list was conducted.As a result, the proposed model correctly evaluated 99% of the 345 leaked passwords.Therefore, the effectiveness of the proposed model was verified.
Reversible Database Watermarking Based on Order-preserving Encryption for Data Sharing

In the era of big data, data sharing not only boosts the economy of the world but also brings about problems of privacy disclosure and copyright infringement. The collected data may contain users’ sensitive information; thus, privacy protection should be applied to the data prior to them being shared. Moreover, the shared data may be re-shared to third parties without the consent or awareness of the original data providers. Therefore, there is an urgent need for copyright tracking. There are few works satisfying the requirements of both privacy protection and copyright tracking. The main challenge is how to protect the shared data and realize copyright tracking while not undermining the utility of the data. In this article, we propose a novel solution of a reversible database watermarking scheme based on order-preserving encryption. First, we encrypt the data using order-preserving encryption and adjust an encryption parameter within an appropriate interval to generate a ciphertext with redundant space. Then, we leverage the redundant space to embed robust reversible watermarking. We adopt grouping and K-means to improve the embedding capacity and the robustness of the watermark. Formal theoretical analysis proves that the proposed scheme guarantees correctness and security. Results of extensive experiments show that OPEW has 100% data utility, and the robustness and efficiency of OPEW are better than existing works.