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Auditing Wallets in Cryptonote
Auditing wallets in CryptoNote sowle <[email protected]> Zano project, https://zano.org Cryptocurrency wallet auditing is the ability for a third party (the "auditor") to watch the transactions and to be able to calculate the correct balance without an ability to spend a coin. This article explores several possible implementations of expansion cryptocurrency protocol CryptoNote 2.0 [1] with such ability. In the original CryptoNote protocol auditing is only partially possible with the help of the tracking key, namely, an auditor is able to distinguish incoming transactions in the blockchain, but the full set of secret keys is required to filter out outgoing transactions. This article is intended for readers familiar with the general blockchain technology and “classic” cryptocurrencies, as well as with the basics of cryptography on elliptic curves. 1. Introduction What is CryptoNote? Surprisingly, most people interested in blockchain technology have never heard anything about CryptoNote, in spite of the fact that the technology has more than 300 forks, including Monero as the most famous. Back in 2014 in the cryptocurrency community there were mentions [2] about a project, titled Bytecoin. That project did not originate as a Bitcoin or other known project fork, having its own original codebase. It was very unusual at the time. Bytecoin general conception was to be an implementation of a privacy-technology named CryptoNote. There were two main privacy mechanisms: stealth-addresses and inputs` mixing-in with the help of ring signatures (at the time it was called "blockchain mixer"). Since Zcash existed only on paper / in theory at that time, CryptoNote became a competitive technology and has provoked much controversy in the cryptocurrency community. -
The Internet and Drug Markets
INSIGHTS EN ISSN THE INTERNET AND DRUG MARKETS 2314-9264 The internet and drug markets 21 The internet and drug markets EMCDDA project group Jane Mounteney, Alessandra Bo and Alberto Oteo 21 Legal notice This publication of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA) is protected by copyright. The EMCDDA accepts no responsibility or liability for any consequences arising from the use of the data contained in this document. The contents of this publication do not necessarily reflect the official opinions of the EMCDDA’s partners, any EU Member State or any agency or institution of the European Union. Europe Direct is a service to help you find answers to your questions about the European Union Freephone number (*): 00 800 6 7 8 9 10 11 (*) The information given is free, as are most calls (though some operators, phone boxes or hotels may charge you). More information on the European Union is available on the internet (http://europa.eu). Luxembourg: Publications Office of the European Union, 2016 ISBN: 978-92-9168-841-8 doi:10.2810/324608 © European Monitoring Centre for Drugs and Drug Addiction, 2016 Reproduction is authorised provided the source is acknowledged. This publication should be referenced as: European Monitoring Centre for Drugs and Drug Addiction (2016), The internet and drug markets, EMCDDA Insights 21, Publications Office of the European Union, Luxembourg. References to chapters in this publication should include, where relevant, references to the authors of each chapter, together with a reference to the wider publication. For example: Mounteney, J., Oteo, A. and Griffiths, P. -
Moneylab Reader: an Intervention in Digital Economy
READER A N INTERVENTION IN DIGITAL ECONOMY FOREWORD BY SASKIA SASSEN EDITED BY GEERT LOVINK NATHANIEL TKACZ PATRICIA DE VRIES INC READER #10 MoneyLab Reader: An Intervention in Digital Economy Editors: Geert Lovink, Nathaniel Tkacz and Patricia de Vries Copy editing: Annie Goodner, Jess van Zyl, Matt Beros, Miriam Rasch and Morgan Currie Cover design: Content Context Design: Katja van Stiphout EPUB development: André Castro Printer: Drukkerij Tuijtel, Hardinxveld-Giessendam Publisher: Institute of Network Cultures, Amsterdam, 2015 ISBN: 978-90-822345-5-8 Contact Institute of Network Cultures phone: +31205951865 email: [email protected] web: www.networkcultures.org Order a copy or download this publication freely at: www.networkcultures.org/publications Join the MoneyLab mailing list at: http://listcultures.org/mailman/listinfo/moneylab_listcultures.org Supported by: Amsterdam University of Applied Sciences (Hogeschool van Amster- dam), Amsterdam Creative Industries Publishing and the University of Warwick Thanks to everyone at INC, to all of the authors for their contributions, Annie Goodner and Morgan Currie for their copy editing, and to Amsterdam Creative Industries Publishing for their financial support. This publication is licensed under Creative Commons Attribution NonCommercial ShareAlike 4.0 Unported (CC BY-NC-SA 4.0). To view a copy of this license, visit http://creativecommons.org/licenses/by-nc-sa/4.0/. EDITED BY GEERT LOVINK, NATHANIEL TKACZ AND PATRICIA DE VRIES INC READER #10 Previously published INC Readers The INC Reader series is derived from conference contributions and produced by the Institute of Network Cultures. They are available in print, EPUB, and PDF form. The MoneyLab Reader is the tenth publication in the series. -
Lab 5: Bittorrent Client Implementation
Lab 5: BitTorrent Client Implementation Due: Nov. 30th at 11:59 PM Milestone: Nov. 19th during Lab Overview In this lab, you and your lab parterner will develop a basic BitTorrent client that can, at minimal, exchange a file between multiple peers, and at best, function as a full feature BitTorrent Client. The programming in this assignment will be in C requiring standard sockets, and thus you will not need to have root access. You should be able to develop your code on any CS lab machine or your personal machine, but all code will be tested on the CS lab. Deliverable Your submission should minimally include the following programs and files: • REDME • Makefile • bencode.c|h • bt lib.c|h • bt setup.c|h • bt client • client trace.[n].log • sample torrent.torrent Your README file should contain a short header containing your name, username, and the assignment title. The README should additionally contain a short description of your code, tasks accomplished, and how to compile, execute, and interpret the output of your programs. Your README should also contain a list of all submitted files and code and the functionality implemented in different code files. This is a large assignment, and this will greatly aid in grading. As always, if there are any short answer questions in this lab write-up, you should provide well marked answers in the README, as well as indicate that you’ve completed any of the extra credit (so that I don’t forget to grade it). Milestones The entire assignment will be submitted and graded, but your group will also hold a milestone meeting to receive feedback on your current implementation. -
Vulnerability of Blockchain Technologies to Quantum Attacks
Vulnerability of Blockchain Technologies to Quantum Attacks Joseph J. Kearneya, Carlos A. Perez-Delgado a,∗ aSchool of Computing, University of Kent, Canterbury, Kent CT2 7NF United Kingdom Abstract Quantum computation represents a threat to many cryptographic protocols in operation today. It has been estimated that by 2035, there will exist a quantum computer capable of breaking the vital cryptographic scheme RSA2048. Blockchain technologies rely on cryptographic protocols for many of their essential sub- routines. Some of these protocols, but not all, are open to quantum attacks. Here we analyze the major blockchain-based cryptocurrencies deployed today—including Bitcoin, Ethereum, Litecoin and ZCash, and determine their risk exposure to quantum attacks. We finish with a comparative analysis of the studied cryptocurrencies and their underlying blockchain technologies and their relative levels of vulnerability to quantum attacks. Introduction exist to allow the legitimate owner to recover this account. Blockchain systems are unlike other cryptosys- tems in that they are not just meant to protect an By contrast, in a blockchain system, there is no information asset. A blockchain is a ledger, and as central authority to manage users’ access keys. The such it is the asset. owner of a resource is by definition the one hold- A blockchain is secured through the use of cryp- ing the private encryption keys. There are no of- tographic techniques. Notably, asymmetric encryp- fline backups. The blockchain, an always online tion schemes such as RSA or Elliptic Curve (EC) cryptographic system, is considered the resource— cryptography are used to generate private/public or at least the authoritative description of it. -
A Decentralized Cloud Storage Network Framework
Storj: A Decentralized Cloud Storage Network Framework Storj Labs, Inc. October 30, 2018 v3.0 https://github.com/storj/whitepaper 2 Copyright © 2018 Storj Labs, Inc. and Subsidiaries This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 license (CC BY-SA 3.0). All product names, logos, and brands used or cited in this document are property of their respective own- ers. All company, product, and service names used herein are for identification purposes only. Use of these names, logos, and brands does not imply endorsement. Contents 0.1 Abstract 6 0.2 Contributors 6 1 Introduction ...................................................7 2 Storj design constraints .......................................9 2.1 Security and privacy 9 2.2 Decentralization 9 2.3 Marketplace and economics 10 2.4 Amazon S3 compatibility 12 2.5 Durability, device failure, and churn 12 2.6 Latency 13 2.7 Bandwidth 14 2.8 Object size 15 2.9 Byzantine fault tolerance 15 2.10 Coordination avoidance 16 3 Framework ................................................... 18 3.1 Framework overview 18 3.2 Storage nodes 19 3.3 Peer-to-peer communication and discovery 19 3.4 Redundancy 19 3.5 Metadata 23 3.6 Encryption 24 3.7 Audits and reputation 25 3.8 Data repair 25 3.9 Payments 26 4 4 Concrete implementation .................................... 27 4.1 Definitions 27 4.2 Peer classes 30 4.3 Storage node 31 4.4 Node identity 32 4.5 Peer-to-peer communication 33 4.6 Node discovery 33 4.7 Redundancy 35 4.8 Structured file storage 36 4.9 Metadata 39 4.10 Satellite 41 4.11 Encryption 42 4.12 Authorization 43 4.13 Audits 44 4.14 Data repair 45 4.15 Storage node reputation 47 4.16 Payments 49 4.17 Bandwidth allocation 50 4.18 Satellite reputation 53 4.19 Garbage collection 53 4.20 Uplink 54 4.21 Quality control and branding 55 5 Walkthroughs ............................................... -
FOIA) Document Clearinghouse in the World
This document is made available through the declassification efforts and research of John Greenewald, Jr., creator of: The Black Vault The Black Vault is the largest online Freedom of Information Act (FOIA) document clearinghouse in the world. The research efforts here are responsible for the declassification of hundreds of thousands of pages released by the U.S. Government & Military. Discover the Truth at: http://www.theblackvault.com Received Received Request ID Requester Name Organization Closed Date Final Disposition Request Description Mode Date 17-F-0001 Greenewald, John The Black Vault PAL 10/3/2016 11/4/2016 Granted/Denied in Part I respectfully request a copy of records, electronic or otherwise, of all contracts past and present, that the DOD / OSD / JS has had with the British PR firm Bell Pottinger. Bell Pottinger Private (legally BPP Communications Ltd.; informally Bell Pottinger) is a British multinational public relations and marketing company headquartered in London, United Kingdom. 17-F-0002 Palma, Bethania - PAL 10/3/2016 11/4/2016 Other Reasons - No Records Contracts with Bell Pottinger for information operations and psychological operations. (Date Range for Record Search: From 01/01/2007 To 12/31/2011) 17-F-0003 Greenewald, John The Black Vault Mail 10/3/2016 1/13/2017 Other Reasons - Not a proper FOIA I respectfully request a copy of the Intellipedia category index page for the following category: request for some other reason Nuclear Weapons Glossary 17-F-0004 Jackson, Brian - Mail 10/3/2016 - - I request a copy of any available documents related to Army Intelligence's participation in an FBI counterintelligence source operation beginning in about 1959, per David Wise book, "Cassidy's Run," under the following code names: ZYRKSEEZ SHOCKER I am also interested in obtaining Army Intelligence documents authorizing, as well as policy documents guiding, the use of an Army source in an FBI operation. -
Creation and Resilience of Decentralized Brands: Bitcoin & The
Creation and Resilience of Decentralized Brands: Bitcoin & the Blockchain Syeda Mariam Humayun A dissertation submitted to the Faculty of Graduate Studies in partial fulfillment of the requirements for the degree of Doctor of Philosophy Graduate Program in Administration Schulich School of Business York University Toronto, Ontario March 2019 © Syeda Mariam Humayun 2019 Abstract: This dissertation is based on a longitudinal ethnographic and netnographic study of the Bitcoin and broader Blockchain community. The data is drawn from 38 in-depth interviews and 200+ informal interviews, plus archival news media sources, netnography, and participant observation conducted in multiple cities: Toronto, Amsterdam, Berlin, Miami, New York, Prague, San Francisco, Cancun, Boston/Cambridge, and Tokyo. Participation at Bitcoin/Blockchain conferences included: Consensus Conference New York, North American Bitcoin Conference, Satoshi Roundtable Cancun, MIT Business of Blockchain, and Scaling Bitcoin Tokyo. The research fieldwork was conducted between 2014-2018. The dissertation is structured as three papers: - “Satoshi is Dead. Long Live Satoshi.” The Curious Case of Bitcoin: This paper focuses on the myth of anonymity and how by remaining anonymous, Satoshi Nakamoto, was able to leave his creation open to widespread adoption. - Tracing the United Nodes of Bitcoin: This paper examines the intersection of religiosity, technology, and money in the Bitcoin community. - Our Brand Is Crisis: Creation and Resilience of Decentralized Brands – Bitcoin & the Blockchain: Drawing on ecological resilience framework as a conceptual metaphor this paper maps how various stabilizing and destabilizing forces in the Bitcoin ecosystem helped in the evolution of a decentralized brand and promulgated more mainstreaming of the Bitcoin brand. ii Dedication: To my younger brother, Umer. -
Understanding the Motivations, Challenges and Needs of Blockchain Software Developers: a Survey
Empirical Software Engineering manuscript No. (will be inserted by the editor) Understanding the Motivations, Challenges and Needs of Blockchain Software Developers: A Survey Amiangshu Bosu · Anindya Iqbal · Rifat Shahriyar · Partha Chakroborty Received: November 6, 2018 / Accepted: March 19, 2019 Abstract The blockchain technology has potential applications in various areas such as smart-contracts, Internet of Things (IoT), land registry, supply chain man- agement, storing medical data, and identity management. Although the Github currently hosts more than six thousand active Blockchain software (BCS) projects, few software engineering research has investigated these projects and its' contrib- utors. Although the number of BCS projects is growing rapidly, the motivations, challenges, and needs of BCS developers remain a puzzle. Therefore, the primary objective of this study is to understand the motivations, challenges, and needs of BCS developers and analyze the differences between BCS and non-BCS development. On this goal, we sent an online survey to 1,604 active BCS developers identified via mining the Github repositories of 145 popular BCS projects. The survey received 156 responses that met our criteria for analysis. The results suggest that the majority of the BCS developers are experienced in non-BCS development and are primarily motivated by the ideology of creating a decentralized financial system. Although most of the BCS projects are Open Source Software (OSS) projects by nature, more than 93% of our respondents found BCS development somewhat different from a non-BCS development as BCS projects have higher emphasis on security and reliability than most of the non- BCS projects. Other differences include: higher costs of defects, decentralized and hostile environment, technological complexity, and difficulty in upgrading the soft- ware after release. -
Hybrid Public/Anonymous Transactions on Monero, Cryptonote X-Cash
Hybrid public/anonymous transactions on Monero, Cryptonote X-Cash Zach Hildreth October 7, 2019 Abstract This yellow paper details the technical concepts and implementation of hybrid transactions (also known as FlexPrivacy c ), a feature enabling public and private transactions on the X- Cash public blockchain. In the first part, the paper aims at detailing how the hybrid transactions operate from a user’s perspective with some real-world use cases. A parallel is made between the digital money system and the economic behaviors associated with the current FIAT system. Secondly, a deeper understanding of the technology is given, explaining the implication on a blockchain perspective, as well as the edge cases and their approaches. Lastly, the last part consists in an in-depth approach of the mathematical concepts and technical implementation of the hybrid transaction in the X-Cash blockchain. Contents 1 Public transactions in the ringCT 4 2 Privacy in the inputs 4 3 A brief understanding of cryptonote transactions 4 4 Creation of a public address 6 5 How stealth addresses/outputs are decoded 6 6 How public transactions are created 7 1 Summary of the public transaction feature The hybrid transaction feature allows users to send and receive public or private transactions on the X-Network Blockchain X-Cash, which is based on the CryptoNote protocol. This feature is implemented on a per transaction basis where users can directly switch the privacy type by choosing the setting before attempting to send a transaction. In a public transaction, the following additional information is made public: • Sender’s address • Receiver’s address • Amount sent • Change amount sent back to the sender’s address However, the public transaction does not compromise the sender’s or receiver’s wallet full bal- ances nor the real mixin (number of signatures in the ring signature that authorizes the transaction) that provided the X-Cash balance. -
State of the Art in Lightweight Symmetric Cryptography
State of the Art in Lightweight Symmetric Cryptography Alex Biryukov1 and Léo Perrin2 1 SnT, CSC, University of Luxembourg, [email protected] 2 SnT, University of Luxembourg, [email protected] Abstract. Lightweight cryptography has been one of the “hot topics” in symmetric cryptography in the recent years. A huge number of lightweight algorithms have been published, standardized and/or used in commercial products. In this paper, we discuss the different implementation constraints that a “lightweight” algorithm is usually designed to satisfy. We also present an extensive survey of all lightweight symmetric primitives we are aware of. It covers designs from the academic community, from government agencies and proprietary algorithms which were reverse-engineered or leaked. Relevant national (nist...) and international (iso/iec...) standards are listed. We then discuss some trends we identified in the design of lightweight algorithms, namely the designers’ preference for arx-based and bitsliced-S-Box-based designs and simple key schedules. Finally, we argue that lightweight cryptography is too large a field and that it should be split into two related but distinct areas: ultra-lightweight and IoT cryptography. The former deals only with the smallest of devices for which a lower security level may be justified by the very harsh design constraints. The latter corresponds to low-power embedded processors for which the Aes and modern hash function are costly but which have to provide a high level security due to their greater connectivity. Keywords: Lightweight cryptography · Ultra-Lightweight · IoT · Internet of Things · SoK · Survey · Standards · Industry 1 Introduction The Internet of Things (IoT) is one of the foremost buzzwords in computer science and information technology at the time of writing. -
A Survey on Volatility Fluctuations in the Decentralized Cryptocurrency Financial Assets
Journal of Risk and Financial Management Review A Survey on Volatility Fluctuations in the Decentralized Cryptocurrency Financial Assets Nikolaos A. Kyriazis Department of Economics, University of Thessaly, 38333 Volos, Greece; [email protected] Abstract: This study is an integrated survey of GARCH methodologies applications on 67 empirical papers that focus on cryptocurrencies. More sophisticated GARCH models are found to better explain the fluctuations in the volatility of cryptocurrencies. The main characteristics and the optimal approaches for modeling returns and volatility of cryptocurrencies are under scrutiny. Moreover, emphasis is placed on interconnectedness and hedging and/or diversifying abilities, measurement of profit-making and risk, efficiency and herding behavior. This leads to fruitful results and sheds light on a broad spectrum of aspects. In-depth analysis is provided of the speculative character of digital currencies and the possibility of improvement of the risk–return trade-off in investors’ portfolios. Overall, it is found that the inclusion of Bitcoin in portfolios with conventional assets could significantly improve the risk–return trade-off of investors’ decisions. Results on whether Bitcoin resembles gold are split. The same is true about whether Bitcoins volatility presents larger reactions to positive or negative shocks. Cryptocurrency markets are found not to be efficient. This study provides a roadmap for researchers and investors as well as authorities. Keywords: decentralized cryptocurrency; Bitcoin; survey; volatility modelling Citation: Kyriazis, Nikolaos A. 2021. A Survey on Volatility Fluctuations in the Decentralized Cryptocurrency Financial Assets. Journal of Risk and 1. Introduction Financial Management 14: 293. The continuing evolution of cryptocurrency markets and exchanges during the last few https://doi.org/10.3390/jrfm years has aroused sparkling interest amid academic researchers, monetary policymakers, 14070293 regulators, investors and the financial press.