An Empirical Study of Namecoin and Lessons for Decentralized Namespace Design
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Linking Wallets and Deanonymizing Transactions in the Ripple Network
Proceedings on Privacy Enhancing Technologies ; 2016 (4):436–453 Pedro Moreno-Sanchez*, Muhammad Bilal Zafar, and Aniket Kate* Listening to Whispers of Ripple: Linking Wallets and Deanonymizing Transactions in the Ripple Network Abstract: The decentralized I owe you (IOU) transac- 1 Introduction tion network Ripple is gaining prominence as a fast, low- cost and efficient method for performing same and cross- In recent years, we have observed a rather unexpected currency payments. Ripple keeps track of IOU credit its growth of IOU transaction networks such as Ripple [36, users have granted to their business partners or friends, 40]. Its pseudonymous nature, ability to perform multi- and settles transactions between two connected Ripple currency transactions across the globe in a matter of wallets by appropriately changing credit values on the seconds, and potential to monetize everything [15] re- connecting paths. Similar to cryptocurrencies such as gardless of jurisdiction have been pivotal to their suc- Bitcoin, while the ownership of the wallets is implicitly cess so far. In a transaction network [54, 55, 59] such as pseudonymous in Ripple, IOU credit links and transac- Ripple [10], users express trust in each other in terms tion flows between wallets are publicly available in an on- of I Owe You (IOU) credit they are willing to extend line ledger. In this paper, we present the first thorough each other. This online approach allows transactions in study that analyzes this globally visible log and charac- fiat money, cryptocurrencies (e.g., bitcoin1) and user- terizes the privacy issues with the current Ripple net- defined currencies, and improves on some of the cur- work. -
Building Resilience & Confronting Risk In
BUILDING RESILIENCE & CONFRONTING RISK IN THE COVID-19 ERA A PARENTS & CAREGIVERS GUIDE TO ONLINE RADICALIZATION POLARIZATION AND EXTREMISM RESEARCH AND INNOVATION LAB (PERIL) PERIL brings the resources and expertise of the university sector to bear CONTENTS on the problem of growing youth polarization and extremist radicalization, through scalable research, intervention, and public education ideas to PARENT & CAREGIVER GUIDE 3 reduce rising polarization and hate. WHAT IS ONLINE RADICALIZATION? WHY SHOULD YOU CARE? 4 SOUTHERN POVERTY LAW CENTER NEW RISKS IN THE COVID-19 ERA 5 The SPLC seeks to be a catalyst for racial justice in the South and RECOGNIZING WARNING SIGNS 6 beyond, working in partnership with communities to dismantle white UNDERSTANDING THE DRIVERS 7 supremacy, strengthen intersectional movements, and advance the ENGAGE AND EMPOWER 9 human rights of all people. RESPONDING TO HATE 11 HOW TO GET HELP 12 APPENDIX: STAYING ALERT TO SITES, PLATFORMS AND APPS FREQUENTLY EXPLOITED BY EXTREMISTS 17 ENDNOTES 19 CREDITS 20 ILLUSTRATIONS BY CLAUDIA WHITAKER PARENT & CAREGIVER GUIDE Who is this guide for? We wrote this guide with a wide Whether you live with a young person, or work virtually range of caregivers in mind. with youth, radicalization to extremism is something we all should be concerned about. Extremists looking Caregivers living with children and young adults. This to recruit and convert children are predatory. Like all includes parents, grandparents, foster parents, extended forms of child exploitation, extremist recruitment drives families, and residential counselors who are the a wedge between young people and the adults they would guardians and caregivers of children and youth living typically trust. -
Ethereum Based Domain Name System Using Smart Contracts
ETHEREUM BASED DOMAIN NAME SYSTEM USING SMART CONTRACTS (BC-DNS) A Project Presented to the faculty of the Department of Computer Science California State University, Sacramento Submitted in partial satisfaction of the requirements for the degree of MASTER OF SCIENCE in Computer Science by Rodney Pinto SPRING 2019 © 2019 Rodney Pinto ALL RIGHTS RESERVED ii ETHEREUM BASED DOMAIN NAME SYSTEM USING SMART CONTRACTS (BC-DNS) A Project by Rodney Pinto Approved by: __________________________________, Committee Chair Dr. Jun Dai. __________________________________, Second Reader Dr. Xuyu Wang. ____________________________ Date iii Student: Rodney Pinto I certify that this student has met the requirements for format contained in the university format manual, and that this project is suitable for shelving in the library and credit is to be awarded for the project. __________________________, Graduate Coordinator ____________________ Dr. Jinsong Ouyang, Ph.D. Date Department of Computer Science iv Abstract of ETHEREUM BASED DOMAIN NAME SYSTEM USING SMART CONTRACTS (BC-DNS) by Rodney Pinto One of the most critical resources that ensure the current working of the internet is the domain name system (DNS). It is a decentralized, hierarchical naming system that is responsible for translating the human-readable domain name to its associated IP address. The use of DNS thus eliminates the need for humans to remember the IP address of all their favorite websites (such as 172.217.6.68 an IPV4 address for google.com). Despite its widespread use, DNS is vulnerable to various security issues. This project focuses on replicating the basic functionality of the existing DNS on the blockchain and deploying it on a peer to peer network making it completely decentralized and, in the process, make it a bit more secure and reliable by addressing few of the security vulnerabilities of the existing system. -
Blocksci: Design and Applications of a Blockchain Analysis Platform
BlockSci: Design and applications of a blockchain analysis platform Harry Kalodner Steven Goldfeder Alishah Chator [email protected] [email protected] [email protected] Princeton University Princeton University Johns Hopkins University Malte Möser Arvind Narayanan [email protected] [email protected] Princeton University Princeton University ABSTRACT to partition eectively. In fact, we conjecture that the use of a tra- Analysis of blockchain data is useful for both scientic research ditional, distributed transactional database for blockchain analysis and commercial applications. We present BlockSci, an open-source has innite COST [5], in the sense that no level of parallelism can software platform for blockchain analysis. BlockSci is versatile in outperform an optimized single-threaded implementation. its support for dierent blockchains and analysis tasks. It incorpo- BlockSci comes with batteries included. First, it is not limited rates an in-memory, analytical (rather than transactional) database, to Bitcoin: a parsing step converts a variety of blockchains into making it several hundred times faster than existing tools. We a common, compact format. Currently supported blockchains in- describe BlockSci’s design and present four analyses that illustrate clude Bitcoin, Litecoin, Namecoin, and Zcash (Section 2.1). Smart its capabilities. contract platforms such as Ethereum are outside our scope. Second, This is a working paper that accompanies the rst public release BlockSci includes a library of useful analytic and visualization tools, of BlockSci, available at github.com/citp/BlockSci. We seek input such as identifying special transactions (e.g., CoinJoin) and linking from the community to further develop the software and explore addresses to each other based on well-known heuristics (Section other potential applications. -
Merged Mining: Curse Or Cure?
Merged Mining: Curse or Cure? Aljosha Judmayer, Alexei Zamyatin, Nicholas Stifter, Artemios Voyiatzis, Edgar Weippl SBA Research, Vienna, Austria (firstletterfirstname)(lastname)@sba-research.org Abstract: Merged mining refers to the concept of mining more than one cryp- tocurrency without necessitating additional proof-of-work effort. Although merged mining has been adopted by a number of cryptocurrencies already, to this date lit- tle is known about the effects and implications. We shed light on this topic area by performing a comprehensive analysis of merged mining in practice. As part of this analysis, we present a block attribution scheme for mining pools to assist in the evaluation of mining centralization. Our findings disclose that mining pools in merge-mined cryptocurrencies have operated at the edge of, and even beyond, the security guarantees offered by the underlying Nakamoto consensus for ex- tended periods. We discuss the implications and security considerations for these cryptocurrencies and the mining ecosystem as a whole, and link our findings to the intended effects of merged mining. 1 Introduction The topic of merged mining has received little attention from the scientific community, despite having been actively employed by a number of cryptocurrencies for several years. New and emerging cryptocurrencies such as Rootstock continue to consider and expand on the concept of merged mining in their designs to this day [19]. Merged min- ing refers to the process of searching for proof-of-work (PoW) solutions for multiple cryptocurrencies concurrently without requiring additional computational resources. The rationale behind merged mining lies in leveraging on the computational power of different cryptocurrencies by bundling their resources instead of having them stand in direct competition, and also to serve as a bootstrapping mechanism for small and fledgling networks [27, 33]. -
Decentralized Reputation Model and Trust Framework Blockchain and Smart Contracts
IT 18 062 Examensarbete 30 hp December 2018 Decentralized Reputation Model and Trust Framework Blockchain and Smart contracts Sujata Tamang Institutionen för informationsteknologi Department of Information Technology Abstract Decentralized Reputation Model and Trust Framework: Blockchain and Smart contracts Sujata Tamang Teknisk- naturvetenskaplig fakultet UTH-enheten Blockchain technology is being researched in diverse domains for its ability to provide distributed, decentralized and time-stamped Besöksadress: transactions. It is attributed to by its fault-tolerant and zero- Ångströmlaboratoriet Lägerhyddsvägen 1 downtime characteristics with methods to ensure records of immutable Hus 4, Plan 0 data such that its modification is computationally infeasible. Trust frameworks and reputation models of an online interaction system are Postadress: responsible for providing enough information (e.g., in the form of Box 536 751 21 Uppsala trust score) to infer the trustworthiness of interacting entities. The risk of failure or probability of success when interacting with an Telefon: entity relies on the information provided by the reputation system. 018 – 471 30 03 Thus, it is crucial to have an accurate, reliable and immutable trust Telefax: score assigned by the reputation system. The centralized nature of 018 – 471 30 00 current trust systems, however, leaves the valuable information as such prone to both external and internal attacks. This master's thesis Hemsida: project, therefore, studies the use of blockchain technology as an http://www.teknat.uu.se/student infrastructure for an online interaction system that can guarantee a reliable and immutable trust score. It proposes a system of smart contracts that specify the logic for interactions and models trust among pseudonymous identities of the system. -
2.3 Blockchain
POLITECNICO DI TORINO Corso di Laurea Magistrale in Ingegneria Informatica - Data Science Tesi di Laurea Magistrale Supporting the portability of profiles using the blockchain in the Mastodon social network Relatore Candidato prof. Giovanni Squillero Alessandra Rossaro Anno Accademico 2018-2019 École polytechnique de Louvain Supporting the portability of profiles using the blockchain in the Mastodon social network Authors: Alessandra ROSSARO, Corentin SURQUIN Supervisors: Etienne RIVIERE, Ramin SADRE Readers: Lionel DRICOT, Axel LEGAY, Giovanni SQUILLERO Academic year 2018–2019 Master [120] in Computer Science Acknowledgements We would like to thank anyone who made the writing of this thesis possible, directly or indirectly. First of all, we would like to thank our supervisors, Prof. Etienne Riviere and Prof. Ramin Sadre for their continous support and advice during the year. We would never have gone this far without them. Secondly, we thank Lionel Dricot, Prof. Axel Legay and Prof. Giovanni Squillero for accepting to be the readers of this thesis. Alessandra First of all, I would like to thank my family, my parents Claudia and Alberto, my brother Stefano and my sister Eleonora, that from the beginning of my studies believed in me, every time urging me to give more and sustaining me each time that I had difficulties. They are my strength and I feel really lucky to have them in my life. Another thanks is to my friends, to Soraya, Beatrice, Sinto and Stefano and especially to Matteo and Edoardo that each time that I needed, remember me to believe in myself and don’t give up. Thank you, sincerely! I would like to thank also my partner, Corentin, because we were a great team, sometimes with some misunderstandings, but I appreciated to work at this project with him! Corentin I must express my deep gratitude to my family and friends for their moral support. -
Download Criminal Complaint Filed in the Eastern District of California
AO 91 (Rev. 11/11) Criminal Complaint UNITED STATES DISTRICT COURT for the Eastern District of California United States of America ) V. ) MARCOS PAULO DE OLIVEIRA ) Case No. ANNIBALE, ) aka "Med3lin," ) aka "Med3lln," ) aka "Med3lln WSM" ) Defendant(s) CRIMINAL COMPLAINT I, the complainant in this case, state that the following is true to the best of my knowledge and belief. On or about the date( s) of October 2017 through April 2019__ in the county of Sacramento in the Eastern District of California , and elsewhere, the defendant(s) violated: Code Section Offense Description 21 U.S.C. §§ 841 and 846 Distribution and Conspiracy to Distribute Controlled Substances 18 U.S.C. §§ 1956 and 1957 Money Laundering This criminal complaint is based on these facts: (see attachment) IX! Continued on the attached sheet. -j- ;1 ·) / , / l 1 - • / L ',;;;_ . _/__I-- / Complainant's signature JAY D. DIAL, Jr., Special Agent Dl'llg Enforcem~_11t Ad111inistration Printed name and title Sworn to before me and signed in my presence. ;]t "-" ' Date: l.2 _/,_ I ---=- (.___ ,,--- "'-~ Judge 's signature City and state: Sacramento, CA Allls__on Claire, U_.§~ Magi~trate__.J__udge Printed name and title AO 91 (Rev. 11/11) Criminal Complaint UNITED STATES DISTRICT COURT for the Eastern District of California United States of America ) V. ) MARCOS PAULO DE OLIVEIRA ) Case No. ANNIBALE, ) aka "Med3lin," ) aka "Med3l1n," ) aka "Med3lln_WSM" ) Defendant(s) CRIMINAL COMPLAINT I, the complainant in this case, state that the following is true to the best of my knowledge and belief. On or about the date(s) of ~tober 20 I 7 through April 2019_ in the county of . -
Impossibility of Full Decentralization in Permissionless Blockchains
Impossibility of Full Decentralization in Permissionless Blockchains Yujin Kwon*, Jian Liuy, Minjeong Kim*, Dawn Songy, Yongdae Kim* *KAIST {dbwls8724,mjkim9394,yongdaek}@kaist.ac.kr yUC Berkeley [email protected],[email protected] ABSTRACT between achieving good decentralization in the consensus protocol Bitcoin uses the proof-of-work (PoW) mechanism where nodes earn and not relying on a TTP exists. rewards in return for the use of their computing resources. Although this incentive system has attracted many participants, power has, CCS CONCEPTS at the same time, been significantly biased towards a few nodes, • Security and privacy → Economics of security and privacy; called mining pools. In addition, poor decentralization appears not Distributed systems security; only in PoW-based coins but also in coins that adopt proof-of-stake (PoS) and delegated proof-of-stake (DPoS) mechanisms. KEYWORDS In this paper, we address the issue of centralization in the consen- Blockchain; Consensus Protocol; Decentralization sus protocol. To this end, we first define ¹m; ε; δº-decentralization as a state satisfying that 1) there are at least m participants running 1 INTRODUCTION a node, and 2) the ratio between the total resource power of nodes Traditional currencies have a centralized structure, and thus there run by the richest and the δ-th percentile participants is less than exist several problems such as a single point of failure and corrup- or equal to 1 + ε. Therefore, when m is sufficiently large, and ε and tion. For example, the global financial crisis in 2008 was aggravated δ are 0, ¹m; ε; δº-decentralization represents full decentralization, by the flawed policies of banks that eventually led to many bank which is an ideal state. -
On the Security of Electroneum Cloud Mining
This Selfie Does Not Exist: On the Security of Electroneum Cloud Mining Alexander Marsalek1, Edona Fasllija2 and Dominik Ziegler3 1Secure Information Technology Center Austria, Vienna, Austria 2Institute for Applied Information Processing and Communications (IAIK), Graz University of Technology, Graz, Austria 3Know-Center GmbH, Graz, Austria Keywords: Electroneum Cloud Mining, Cryptocurrency, Impersonation Attack, Image Manipulation. Abstract: The Electroneum cryptocurrency provides a novel mining experience called “cloud mining”, which enables iOS and Android users to regularly earn cryptocurrency tokens by simply interacting with the Electroneum app. Besides other security countermeasures against automated attacks, Electroneum requires the user to up- load selfies with a predefined gesture or a drawing of a symbol as a prerequisite for the activation of the mining process. In this paper, we show how a malicious user can circumvent all of these security features and thus create and maintain an arbitrary number of fake accounts. Our impersonation attack particularly focuses on creating non-existing selfies by relying on Generative Adversarial Network (GAN) techniques during account initialization. Furthermore, we employ reverse engineering to develop a bot that simulates the genuine Elec- troneum app and is capable of operating an arbitrary number of illegitimate accounts on one Android device, enabling the malicious user to obtain an unfairly large payout. 1 INTRODUCTION Rivet, 2019). Due to these effects, both Google and Apple prohibit cryptocurrency mining apps from their During 2017, the first and most popular cryptocurrency, application stores (Apple, 2019; Google, 2018), limiting Bitcoin, experienced an astonishing 13-fold increase in the accessibility of the average smartphone users to crypto mining. Despite this fact, several projects like value (Corcoran, 2017). -
TITLE PAGE Bitcoin and Stock Markets. Are They Connected? Evidence from Asean Emerging Economies Abdollah Ah Mand*1, Hassanudin
Bitcoin and Stock Markets: Are They Connected? Evidence from Asean Emerging Economies Abdollah Ah Mand ( [email protected] ) Sunway University Hassanudin Mohd Thas Thaker Sunway University Research Keywords: Cryptocurrencies, bitcoin, stock market, emerging economies Posted Date: May 12th, 2020 DOI: https://doi.org/10.21203/rs.3.rs-25524/v1 License: This work is licensed under a Creative Commons Attribution 4.0 International License. Read Full License TITLE PAGE Bitcoin and Stock Markets. Are they Connected? Evidence from Asean Emerging Economies Abdollah Ah Mand*1, Hassanudin Mohd Thas Thaker2 Email of corresponding author: [email protected] 1,2 Sunway University, Malaysia Abstract Background: Cryptocurrencies, especially Bitcoin, has become popular for investors in recent years. The volatility of bitcoin and time horizon are the center point for investment decisions. However, attention is not often drawn to the relationship between bitcoin and equity indices. This study investigates the volatility and time frequency domain of bitcoin among five Asean countries through a rich database which covers daily data from July 2010 until April 2019. Methods: Advanced econometrics and Wavelets Cross-Coherence Spectrograms, this study investigates the existence of long run association between bitcoin and the studied market indices. M-GARCH analysis is been employed to investigate the unconditional volatility of market indices and Bitcoin. Results: The findings present the long run association with positive (Philippines) and negative (Japan, Korea, Singapore, Hong Kong) relations. Moreover, only one market (KOREA) shows a short run association with bitcoin. The M- GARCH analysis reveals, most of the selected Asean countries have a low unconditional volatility with bitcoin. -
Identifier System Attack Mitigation Methodology DATE: 13 February 2017 Identifier System Attack Mitigation Methodology
Identifier System Attack Mitigation Methodology DATE: 13 February 2017 Identifier System Attack Mitigation Methodology Introduction This document is part of ICANN’s effort to contribute to enhancing the Stability, Security, and Resiliency (SSR) of the Internet’s system of unique identifiers (“Internet Identifiers”) by working with the Community to identify and increase awareness of related attacks and to promote broader adoption of attack mitigation practices. This effort also addresses Recommendation #12 of the Security, Stability & Resiliency (SSR) Review Team (SSR-RT) by creating an Identifier System Attack Mitigation Methodology. Specifically, this document identifies and prioritizes types of attacks against the Identifier System, providing a stepping-off point for ICANN to coordinate with the Community to develop a series of short technical documents (“Tech Notes”) on actual high-impact attacks and emerging high-risk vulnerabilities. This document will be periodically updated to reflect evolution of both the Identifier System and the cybercrime landscape, supporting on-going efforts within both ICANN and the Community to mitigate attacks that pose the greatest risk to Identifier System SSR. Authors: Lisa Phifer and David Piscitello Page 1 Identifier System Attack Mitigation Methodology DATE: 13 February 2017 Attack Mitigation Methodology ICANN is proposing a new Identifier System Attack Mitigation Methodology to: • Identify, prioritize, and periodically refresh a list of top Identifier System attacks; • Develop guidance on actual high-impact attacks and emerging high-risk vulnerabilities; • Describe corresponding attack mitigation practices that are commonly considered useful; and • Encourage broader adoption of those practices via contracts, agreements, incentives, etc. This document represents the first component of this methodology.