Laura Ricci

• PhD in Computer Science
• Professor (Associate) at University of Pisa

The increasing adoption of tokens on the Ethereum blockchain has given rise to many distinct economic communities whose activity history is publicly accessible. In this paper we study the communities of Ethereum fungible and non-fungible tokens, regulated, respectively, by the ERC-20 and ERC-721 standards. In particular, we focus on token transfers...

The transparent nature of public blockchain systems allows for unprecedented access to economic community data. Examples of such communities are the fungible token networks created by the ERC-20 standard on the Ethereum protocol. In this paper we study ERC-20 token networks, where nodes represent users and edges represent fungible token transfers b...

The recent interest for decentralised systems and decentralisation of the control over users' data brings a shift in the way identities and their information are managed. Self Sovereign Identity (SSI) has been proposed as the next generation paradigm for decentralised identity management. Research on SSI is getting more and more traction, focusing...

Decentralized Online Social Networks (DOSNs) have recently captured the interest of users because of the more control given to the end users over their shared social contents. Indeed, user privacy issues related to the centralized Online Social Network (OSN) services (such as Facebook or Google+) does not apply in the case of DOSNs because of the a...

In the Bitcoin protocol, dust refers to small amounts of currency that are lower than the fee required to spend them in a transaction. Although “economically irrational”, dust is commonly used for achieving unconventional side effects, rather than exchanging value. For instance, dust might be linked to on-chain services or to malicious activity, su...

Blockchain is a disruptive technology and incredibly popular nowadays based on decentralized ledger technology. It is a tampered-proof technology that saves the transaction data permanently in a distributed ledger with an immutable time-stamped series record of data, and it is built on the idea of a peer-to-peer network. Blockchain efficiently crea...

Dust refers to the amounts of cryptocurrency that are smaller than the fees required to spend them in a transaction. Due to its “economically irrational” nature, dust is often used to achieve some external side effect, rather than exchanging value. In this paper we study this phenomenon by conducting an analysis of dust creation and consumption in...

Online Social Media (OSM) are dominating the wide range of Internet services. Due to their vast audience, it is crucial to evaluate the interpersonal trust among OSM users that can identify reliable sources of information, the meaningfulness of a relationship, or the trustworthiness of other users. SentiTrust is an innovative trust model for Decent...

The modernization of voting methods is a dynamic area of research currently. In the past, innovation in voting methodswas limited to the automation of steps in the process through mechanical means. This changed with the introduction of commercial cryptography in the 1970s, whose applications to voting triggered a new era in this research field. Res...

The blockchain technology has been gaining an increasing popularity in the last years, and smart contracts are being used for a growing number of applications in several scenarios. The execution of smart contracts on public blockchains can be invoked by any user with a transaction, although in many scenarios there would be the need for restricting...

Many decentralised systems can be represented as graphs, and the detection of their community structure can uncover important properties. Several community detection algorithms have been proposed, however, only a few solutions are suitable for detecting and managing communities in a distributed and highly dynamic environment. This lacking is mainly...

In recent years, Decentralized Online Social Networks (DOSNs) have been attracting the attention of many users because they reduce the risk of censorship, surveillance, and information leakage from the service provider. In contrast to the most popular Online Social Networks, which are based on centralized architectures (e.g., Facebook, Twitter, or...

Opportunistic computing is a paradigm for completely self-organised pervasive networks. Instead of relying only on fixed infrastructures as the cloud, users' devices act as service providers for each other. They use pairwise contacts to collect information about services provided and amount of time to provide them by the encountered nodes. At each...

Online social networks (OSNs) revolutionized how people interact with each other, and nowadays, thanks to blockchain technology, new solutions are being considered, giving birth to blockchain online social media (BOSMs). BOSMs use the blockchain to redistribute with their users the wealth generated by the platform through a rewarding system, assign...

In many blockchain networks, light nodes (e.g. mobile clients) with few computational resources must rely on more powerful full nodes to retrieve transactions from the chain. However, in this untrusted environment a malicious full node could deliver altered or incomplete information, requiring query authentication techniques to ensure the integrity...

Online Social Networking platforms (OSNs) have become part of people’s everyday life and their usage covers the deep-rooted need for communication among humans. During recent years, as people are questioning more and more OSN service providers, a new generation of proposals, based on blockchain became very popular thanks to the ethics adopted by th...

Internet of Things (IoT) security, privacy and trust remain the major challenges, mainly due to the massive scale and distributed nature of IoT networks. Access control systems are used in security to control access to valuable resources. This paper proposes a novel trust-based access control (TACL) model for IoT. Trust provides IoT devices with a...

In the last decades, temporal networks played a key role in modelling, understanding, and analysing the properties of dynamic systems where individuals and events vary in time. Of paramount importance is the representation and the analysis of Social Media, in particular Social Networks and Online Communities, through temporal networks, due to their...

The widespread adoption of Online Social Networks (OSNs), the ever-increasing amount of information produced by their users, and the corresponding capacity to influence markets, politics, and society, have led both industrial and academic researchers to focus on how such systems could be influenced . While previous work has mainly focused on measur...

Several blockchain projects to help against COVID-19 are emerging at a fast pace, showing the potential of this disruptive technology to mitigate the multi-systemic threats the pandemic is posing on all phases of the emergency management and generate value for the economy and society as a whole. This survey investigates how blockchain technology ca...

Recommender Systems (RSs) are becoming increasingly popular in the last years. They collect reviews concerning several types of items (e.g., shops, professionals, services, songs or videos) in order to rank them according to a given criterion, and to suggest the most relevant ones to their users. However, most of the currently used RSs exhibit two...

The impact of Online Social Networks (OSNs) on the world has changed the way people interact with each other. During the last years, the trend to build virtual communities based on common interests, also called online social groups, has affirmed. Online social groups have been studied in the past, however, several aspects concerning the relationshi...

The Interplanetary File System (IPFS) seeks to build a decentralized, fast and efficient file system able to connect all devices worldwide. In particular, its decentralized nature makes it viable to be applied to other decentralized applications, such as Decentralized Online Social Networks. Several Blockchain Online Social Networks adopted IPFS fo...

Online social networks (OSNs) have changed the way of how people interact; however, lately, people are questioning more and more their business models. During the last ten years, new solutions based on decentralized architectures have been proposed, namely, decentralized OSNs (DOSNs) and blockchain online social medias (BOSMs). DOSNs were introduce...

Recommender Systems are very popular tools within the online community, suggesting to their users a big variety of items like products, videos, music and locations to visit. Moreover, users actively populate these systems sending and reading opinions under the form of reviews, and potentially obtaining a reward for their activities. However, such s...

The emerging Smart Agriculture based on Internet of Things (IoT) is facing major challenges like data sharing, storage, and monitoring, primarily due to the distributed nature of IoT and massive scale. We performed a review of the literature and found that blockchain performance, scalability, cost, and throughput are the major challenges in adoptin...

Since their introduction, Online Social Networks (OSNs) have transformed the way people interact with each other. Lately, a new trend is rising in the development of OSNs, fueled by an increasing interest of the blockchain technology and the benefits it can bring to the world of OSNs. Blockchain Online Social Media (BOSMs) are Social Media applicat...

Cryptocurrencies are notorious for their exchange rate high volatility, and are often tools of wild speculation rather than decentralised value exchange. This is especially true for Bitcoin, still, nowadays, the most popular cryptocurrency. This paper presents an analysis to detect the influence of a set of topological properties of the Bitcoin Use...

Internet has completely evolved in recent years, and smart devices, such as mobile and IoT devices have become pervasive in the daily life of people. Internet is becoming more social, and Online Social Networking platforms (OSNs) have become part of the real life of people. Current Online Social Media platforms are centralized. Centralization prese...

Trust and risk issue in distributed environments represent today an important research topic. Access Control Systems are mainly used in security to control access to resources. Access control policies are used to express the rights of users to access resources. In this paper, the Blockchain is used as a tool for location-aware Role-based access con...

Chapter "In Situ Visualization of Performance-Related Data in Parallel CFD Applications" is available open access under a Creative Commons Attribution 4.0 International License via link.springer.com.

The increasing pervasive and ubiquitous presence of devices at the edge of the Internet is creating new scenarios for the emergence of novel services and applications. This is particularly true for location and context-aware services. These services call for new decentralized, self-organizing communication schemes that are able to face issues relat...

The Blockchain is a novel technology with a wide range of potential industrial applications. Despite a vast range of tests, prototypes, and proof of concepts implemented in the last years, the industrial use of Blockchain technology is still in the early stages. Enabling the interaction of industrial Internet of Things (IOT) platforms with Blockcha...

The Blockchain is a novel technology with a wide range of potential industrial applications. Despite a vast range of tests, prototypes, and proof of concepts implemented in the last years, the industrial use of Blockchain technology is still in the early stages. Enabling the interaction of industrial Internet of Things (IOT) platforms with Blockcha...

Access Control systems are a key resource in computer security to properly manage the access to digital resources. Blockchain technology, instead, is a novel technology to decentralise the control and management of a shared state, representing anything from a data repository to a distributed virtual machine. We propose to integrate traditional Acce...

The widespread adoption of Online Social Networks (OSNs) and the ever-increasing amount of information produced by their users has led both industrial and academic researchers to focus on how such systems could be influenced. Recent results show that measuring and predicting the influence of the OSNs' users has direct applications in economy, polit...

Decentralized Online Social Networks (DOSNs) have been proposed as an alternative solution to the current centralized Online Social Networks (OSNs). Online Social Networks are based on centralized architecture (e.g., Facebook, Twitter, or Google+), while DOSNs do not have a service provider that acts as central authority and users have more control...

Nowadays information available on the World Wide Web has reached unprecedented growth and it makes difficult for users to find the most relevant for them. In order to alleviate such issue, Recommender Systems (RSs) have been proposed to collect opinions and preferences about a set of items, process such preferences and build a personalized informat...

The applications of Blockchain and Smart Contracts cover all aspects of digital information processing, varying from Asset Management platforms to Online Shops and Digital Identity Management. Several start-up companies and fellow researchers are interested in creating decentralized Clouds using the Blockchain as the mechanism for synchronization,...

Decentralized Online Social Networks (DOSNs) have been proposed as an alternative solution to the current centralized Online Social Networks (OSNs). Online Social Networks are based on centralized architecture (e.g., Facebook, Twitter, or Google+), while DOSNs do not have a service provider that acts as central authority and users have more control...

With the rapid development and growth of online social networks (OSNs), researchers have been pushed forward to improve the knowledge of these complex networks by analyzing several aspects, such as the types of social media, the structural properties of the network, or the interaction patterns among users. In particular, a relevant effort has been...

The availability of the entire Bitcoin transaction history, stored in its public blockchain, offers interesting opportunities for analysing the transaction graph to obtain insight on users behaviour. This paper presents an analysis of the Bitcoin users graph, obtained by clustering the transaction graph, to highlight its connectivity structure and...

Most democratic countries still use the traditional systems of paper ballots and voting boxes. As technology develops, new electronic voting systems have been proposed to modernize and facilitate the voting process. Most e-voting systems are based on centralizing models, i.e. client-server structures, which have been proved to be unreliable and pro...

This work proposes to exploit blockchain technology to define Access Control systems that guarantee the auditability of access control policies evaluation. The key idea of our proposal is to codify attribute-based Access Control policies as smart contracts and deploy them on a blockchain, hence transforming the policy evaluation process into a comp...

Internet of Thing (IoT) can be generally defined as a network connecting millions of smart objects, most of them equipped with sensors. Since sensors are devices generating a huge amount of data, the transmission of raw data to the edge nodes and then to higher level cloud nodes may give rise to transmission delays and energy consumption. Furthermo...

In this paper we study the structure of the Bitcoin users graph derived from the transactions data stored in the Bitcoin blockchain. This work analyzes the macroscopic structure of the connectivity components of such graph. As our graph represents an economic community, we give an economical interpretation of the different components. To do so we a...

The problem of protecting sensitive data like medical records, and enabling the access only to authorized entities is currently a challenge. Current solutions often require trusting some centralized entity which is in charge of managing the data. The disruptive technology of blockchains may offer the possibility to change the current scenario and g...

During the last ten years, Online Social Networks (OSNs) have increased their popularity by becoming part of the real life of users. Despite their tremendous widespread, OSNs have introduced several privacy issues as a consequence of the nature of the information involved in these services. Indeed, the huge amount of private information produced by...

The widespread diffusion of Online Social Networks has given unforeseen opportunities for their users to share contents and mutually interact. However, current platforms offer inadequate guarantees as far as concerns the privacy of their users. To address these issues and leave to the users more control on their data, several recent proposals sugge...

This paper presents a new design approach for Access Control services leveraging smart contracts provided by blockchain technology. The key idea of our proposal is to codify Access Control policies as executable smart contracts on a blockchain. This transforms the policy evaluation process into completely distributed smart contract executions. In o...

Data analytic has recently enabled the uncovering of interesting properties of several complex networks. Among these, it is worth considering the bitcoin blockchain, because of its peculiar characteristic of reflecting a niche, but also a real economy whose transactions are publicly available. In this paper, we present the analyses we have performe...

Bitcoin has emerged as a disruptive technology able to revolutionize the way financial transactions are performed. The static analysis of the Bitcoin's blockchain conducted jointly with a real time analysis of the Bitcoin's Peer-to-Peer network can reveal interesting properties of the Bitcoin's ecosystem. In this paper we propose BitKer, a Bitcoin...

The study of complex networks has acquired great importance during the last years because of the diffusion of several phenomena which can be described by these networks. Community detection is one of the most investigated problem in this area, however only a few solutions for detecting communities in a distributed and dynamic environment have been...

Opportunistic computing is a paradigm for completely self-organised pervasive networks. Instead of relying only on fixed infrastructures as the cloud, users' devices act as service providers for each other. They use pairwise contacts to collect information about services provided and amount of time to provide them by the encountered nodes. At each...

The large diffusion of Online Social Networks (OSNs) has influenced the way people interact with each other. OSNs present several drawbacks, one of the most important is the problem of privacy disclosures. Distributed Online Social Networks (DOSNs) have been proposed as a valid alternative solution to solve this problem. DOSNs are Online Social Net...