1,720,956 research outputs found
Blockchain-based Data Immutability and Traceability in the Era of GDPR
No full textBlockchain technology and smart contracts have recently emerged as valid tools for implementing applications dealing with data due to their ability to provide immutability, traceability, and availability properties. However, in recent years, applications dealing with data need to comply with some data protection regulations, such as the GDPR in Europe. These regulations typically specify a set of rights for data subjects, like the right to be forgotten or the right to rectification, that are apparently in contrast with the blockchain properties mentioned above. This paper investigates how the eight data subject rights prescribed by the GDPR could be supported by a proper combination of blockchain, smart contracts, and encryption techniques. The discussion will proceed in an incremental way by describing how increased support for the GDPR rights requires increased sophistication of the provided solution
Adaptive Multi-Factor Scoring in Shared Blob for Improving Data Availability in Layer 2 Blockchains
No full textLayer 2 (L2) solutions have recently been developed with the aim of increasing scalability and throughput of traditional blockchain networks such as Bitcoin and Ethereum. The main idea of L2 is to move expensive computations out of the main (L1) network and post back only a summary of the performed transactions. This allows L2 solutions to inherit the security and trustworthiness of L1 while reducing computation and transaction costs. However, data availability, namely the possibility for all blockchain participants to access the data processed outside L1 to verify state transitions independently, is a challenge in L2 solutions. Namely, while on-chain data availability approaches suffer from high costs and long waiting times, off-chain approaches can pose data security risks. This paper takes into consideration the recent introduction of the blob data structure and proposes an Adaptive Multi-Factor Scoring (AMFS) to efficiently manage blobs while dynamically optimizing cost and waiting time. The proposed solution ensures low waiting times and blob posting costs, particularly for small rollups, by implementing the concept of shared blob, maintaining security without compromising performance
Blockchain-Based Multirole Authentication and Authorization in Smart Contracts with a Hierarchical Factory Pattern
No full textThe recent spread of smart contracts in several application domains presents challenges in scalability, efficiency, management, and security. In this regard, some design patterns have been proposed to factorize common parts, prevent replicated deployment by promoting reusability, and apply some role-based access control (RBAC) techniques during smart contract execution. In particular, the factory pattern has been widely recognized as a common practice to solve the scalability issue, reducing also the increased gas costs related to both smart contract deployment and its subsequent use. However, in real-world applications, the factory pattern can be considered too limited since it only allows the instantiation of a single type or family of contracts. On the other side, no solutions have been proposed that tightly integrate a factory pattern with RBAC functionalities. In this paper, we propose an extension of the factory pattern, called the hierarchical factory pattern, which integrates a multirole authentication and authorization mechanism tailored explicitly to this pattern since it allows a secure, efficient, and role-specific interaction between the various layers of the hierarchy. The paper ends with some considerations about performance and scalability
A Survey on Data Availability in Layer 2 Blockchain Rollups: Open Challenges and Future Improvements
Full text linkBlockchain technology has been successfully applied in recent years to promote the immutability, traceability, and authenticity of previously collected and stored data. However, the amount of data stored in the blockchain is usually limited for economic and technological issues. Namely, the blockchain usually stores only a fingerprint of data, such as the hash of data, while full, raw information is stored off-chain. This is generally enough to guarantee immutability and traceability, but misses to support another important property, that is, data availability. This is particularly true when a traditional, centralized database is chosen for off-chain storage. For this reason, many proposals try to properly combine blockchain with decentralized IPFS storage. However, the storage of data on IPFS could pose some privacy problems. This paper proposes a solution that properly combines blockchain, IPFS, and encryption techniques to guarantee immutability, traceability, availability, and data privacy
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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