Darknet: Mýtus a Realita Kybernetického Prostoru Bakalářská Diplomová Práce

Total Page:16

File Type:pdf, Size:1020Kb

Darknet: Mýtus a Realita Kybernetického Prostoru Bakalářská Diplomová Práce Masarykova univerzita Filozofická fakulta Ústav hudební vědy Teorie interaktivních médií Vojtěch Drbola Darknet: mýtus a realita kybernetického prostoru Bakalářská diplomová práce Vedoucí práce: PhDr. Martin Flašar, Ph.D. Brno 2016 Prohlašuji, že jsem diplomovou práci vypracoval samostatně s využitím uvedených pramenů a literatury. V Brně, dne 9. 12. 2016 .................................................. Vojtěch Drbola Poděkování Chtěl bych poděkovat především PhDr. Martinu Flašarovi Ph.D. za vedení práce, cenné rady a podporu během jejího psaní. Obsah 1 Úvod ...................................................................................................................................... 4 2 Evil media ............................................................................................................................. 6 3 Darknet vs. Deep web ........................................................................................................... 8 4 Darknet .................................................................................................................................. 9 4.1 Mýty o Darknetu ........................................................................................................... 10 4.2 Kybernetické tržiště na Darknetu ................................................................................. 11 4.3 Filozofie Silkroad a Strašlivý pirát Roberts ................................................................. 15 5 Tor ....................................................................................................................................... 24 6 Kryptoměny ......................................................................................................................... 27 6.1 Bitcoin .......................................................................................................................... 27 6.1.1 Nákup Bitcoinu ...................................................................................................... 28 6.1.2 Bitcoin a anonymita ............................................................................................... 29 6.1.3 Cena Bitcoinu a jeho množství .............................................................................. 30 6.2 Litecoin ......................................................................................................................... 32 6.3 Monero.......................................................................................................................... 32 7 Rozcestníky ......................................................................................................................... 34 8 Temná místa Darknetu ........................................................................................................ 36 9 Praktická část ....................................................................................................................... 39 9.1 Dotazník pro neuživatele Darknetu .............................................................................. 39 9.2 Dotazník pro uživatele Darknetu. ................................................................................. 51 9.3 Srovnání odpovědí. ....................................................................................................... 63 9.3.1 Společné otázky: .................................................................................................... 63 9.4 Shrnutí: ......................................................................................................................... 67 10 Závěr .................................................................................................................................. 69 11 Resumé .............................................................................................................................. 71 12 Summary ........................................................................................................................... 71 13 Seznam použitých pramenů a literatury ............................................................................ 72 1 Úvod Tématem bakalářské práce je skrytý virtuální prostor Darknet, který je hned z počátku práce zařazen do konceptu Evil media. Definuje pojem Darknet a poukazuje na rozdíly mezi Darknetem, Deepwebem a Surfacewebem. Rozebírá internetový prohlížeč Tor fungující na systému onion routingu a ukazuje rozdíly oproti běžnému prohlížeči. Práce dále rozebírá kryptoměny Bitcoin, Litecoin a Monero, které jsou dnes nedílnou součástí internetových plateb a jsou běžně využívané na Darknetu k provádění transakcí. Dále pak ukazuje způsoby, jak se na Darknetu orientovat a úspěšně najít požadovaný obsah. Cílem práce je co nejvíce popsat Darknet a způsoby, jakými se dá připojit k tomuto virtuálnímu prostoru. Dále pak poukázat na mýty, které jsou o Darknetu šířeny, a srovnat je s reálným obsahem. Prezentuje nejnavštěvovanější stránky na Darknetu, kterými jsou virtuální tržiště, převážně určená k ilegální činnosti, a popisuje je. Práce dále rozebírá nejznámější tržiště Silkroad od jeho vzniku až po stáhnutí z provozu. Poukazuje na striktní filozofii, kterou je zajímavé nejen tohle tržiště, ale také osoba Strašlivého piráta Robertse, který je považován za zakladatele Silkroad. Uvádí kauzu týkající se Strašlivého piráta Robertse spolu s otázkami týkajícími se legislativy této kauzy. Klade důraz na uvědomění si možností monitoringu veškerých kroků jakéhokoliv uživatele při připojování k internetu a na spojitosti mezi žádanou online anonymitou a možným monitoringem. Práce je rozdělena na část teoretickou a praktickou. V praktické části předkládá kvalitativní dotazníky ohledně internetové bezpečnosti, anonymity aj. uživatelům i neuživatelům Darknetu. Závěrem práce vyhodnocuje odpovědi od obou druhů respondentů, srovnává a interpretuje odpovědi u společných otázek. Na podobné téma byla napsána bakalářská práce s názvem Darknet: fikce či realita skrytých služeb Tor a systému Bitcoin1 od Roberta Volejníka. V této práci byla hlavním tématem anonymita uživatelů Darknetu a popis nutných programů k jejímu docílení, dále pak podrobně rozebraná kryptoměna Bitcoin. Bakalářská práce Darknet: Mýtus či realita kybernetického prostoru se naopak zabývá především Darknetem a mýty, které jsou o tomto virtuálním prostoru zveřejňovány. Poukazuje na realitu, že Darknet je využíván i legálními 1 VOLEJNÍK, Robert (2016). Darknet: fikce či realita skrytých služeb Tor a systému Bitcoin. Brno, 2016. Bakalářská práce. Masarykova univerzita. 4 způsoby a tyto způsoby prezentuje. Dále se liší v praktické části, ve které analyzuje a interpretuje odpovědi z kvalitativních dotazníků od uživatelů a neuživatelů Datknetu. Téma práce jsem si vybral především z důvodu dlouhodobého zájmu o Darknet a mýty, které ohledně tohoto virtuálního prostoru kolují. Veškeré informace, které tato bakalářská práce obsahuje, slouží pouze k výzkumným a studijním účelům. 5 2 Evil media Pojem Evil media vznikl současně s rozvíjejícími se novými médii, která jsou primárně založena na digitálním kódování dat. Vznik nových médií sahá již do počátku 19. století, ovšem začal se razantně rozšiřovat právě s příchodem digitálního kódu a internetu, k nimž se váže prudké šíření digitálních technologií. Matthew Fuller a Andrew Goffey, autoři knihy Evil media píší: „Evil media studies is not a discipline, nor is it the description of a category of particularly unpleasant media objects. It is a manner of working with a set of informal practices and bodies of knowledge, characterized as stratagems, which pervade contemporary networked media and which straddle the distinction between the work of theory and of practice.“2 Digitální technologie jsou nyní nezbytnou součástí našich životů. Evil media jsou taková, která porušují hranici mezi teorií a praxí způsobem, jež není společností akceptován. V mnohých případech společnost o existenci zlých médií nemá ani tušení, jelikož se netváří, jako média zlá nebo se maskují za zastaralý model. Zlá média mohou být také spojována se stářím daného média. Příkladem toho je internet. Se spuštěním v devadesátých letech 20. století se internet stává hlavním proudem inovací, a to nejen karierním. Lidé v té době vlastně ještě pořádně nevěděli, co je to internet, jaké možnosti může skrývat. V počátku mohl být internet potencionálně více zlým médiem, než je tomu dnes. Rozšířily se technologie blokující dětem pornografické stránky, programy dostatečně chránící běžného uživatele proti útokům hackerů, první virtuální tržiště na Darknetu byly zabaveny FBI atd. Darknet je nedílnou součástí internetu, který původně, jako internet samotný, nebyl stvořen k porušování zákonů, ale k vládním a akademickým účelům. I přesto, že Darknet můžeme datovat souběžně s internetem, je pro veřejnost mnohem novější. Mluvit se o něm začalo až díky kauze tržiště Silkroad, virtuálnímu obchodu s drogami a dalším zbožím. Do provozu bylo tržiště uvedeno v roce 2011. Tato část internetu je známa především pro vykonávání ilegální činnosti, ovšem Darknet obsahuje mnohem širší spektrum možností, ať už se jedná o využití vládou, institucemi a médii, Darknet spadá do konceptu zlých médií velmi podobně jako internet samotný, jelikož je jeho součástí. Ovšem boj proti sociálně neakceptovatelné činnosti je na Darknetu mnohem více náročný (v mnoha případech nemožný) 2 FULLER, Matthew – GOFFEY, Andrew. Towards an Evil Media Studies [online]. New Jersey: Hampton Press, 2007, s. 141 [cit. 19. 10. 2016]. Dostupné z: <http://xenopraxis.net/readings/fuller_goffey_evilmediaSHORT.pdf>.
Recommended publications
  • A Probe Survey of Bitcoin Transactions Through Analysis of Advertising in an On-Line Discussion Forum
    Acta Informatica Pragensia, 2019, 8(2), 112–131 DOI: 10.18267/j.aip.127 Original Article A Probe Survey of Bitcoin Transactions Through Analysis of Advertising in an On-Line Discussion Forum Zoltan Ban 1, Jan Lansky 1, Stanislava Mildeova 1, Petr Tesar 1 Abstract Cryptocurrencies have become a major phenomenon in recent years. For IT, a breakthrough is both the cryptocurrency itself as a commodity and the technology that cryptocurrency development has brought. The article focuses on the bitcoin cryptocurrency as the most important cryptocurrency. A relatively unexplored topic is what goods or services are purchased for bitcoins. To track what bitcoins are spent on, it is necessary to look for places that are dedicated to trading cryptocurrencies. The bitcointalk.org forum was chosen as a source for our data mining. The aim of the article is to find an answer to the research question: What are bitcoins on the discussion forum bitcointalk.org planned to be spent on? As part of the research, an application was developed using a PHP script to gather information from the discussion forum (bitcointalk.org). There is some evidence which suggests what types of products or services people spend cryptocurrencies on. This research has proven that cryptocurrencies are used to buy and sell goods or services in the electronics and computer world segments. Today, these segments are widespread, which may speed up the integration of cryptocurrencies into everyday life. This applies, of course, only if the risks associated with cryptocurrencies do not increase. Keywords: Cryptocurrency, Bitcoin, On-Line Advertisement, Text Mining, Cybersecurity, Discussion Forum.
    [Show full text]
  • 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 .
    [Show full text]
  • Transparent and Collaborative Proof-Of-Work Consensus
    StrongChain: Transparent and Collaborative Proof-of-Work Consensus Pawel Szalachowski, Daniël Reijsbergen, and Ivan Homoliak, Singapore University of Technology and Design (SUTD); Siwei Sun, Institute of Information Engineering and DCS Center, Chinese Academy of Sciences https://www.usenix.org/conference/usenixsecurity19/presentation/szalachowski This paper is included in the Proceedings of the 28th USENIX Security Symposium. August 14–16, 2019 • Santa Clara, CA, USA 978-1-939133-06-9 Open access to the Proceedings of the 28th USENIX Security Symposium is sponsored by USENIX. StrongChain: Transparent and Collaborative Proof-of-Work Consensus Pawel Szalachowski1 Daniel¨ Reijsbergen1 Ivan Homoliak1 Siwei Sun2;∗ 1Singapore University of Technology and Design (SUTD) 2Institute of Information Engineering and DCS Center, Chinese Academy of Sciences Abstract a cryptographically-protected append-only list [2] is intro- duced. This list consists of transactions grouped into blocks Bitcoin is the most successful cryptocurrency so far. This and is usually referred to as a blockchain. Every active pro- is mainly due to its novel consensus algorithm, which is tocol participant (called a miner) collects transactions sent based on proof-of-work combined with a cryptographically- by users and tries to solve a computationally-hard puzzle in protected data structure and a rewarding scheme that incen- order to be able to write to the blockchain (the process of tivizes nodes to participate. However, despite its unprece- solving the puzzle is called mining). When a valid solution dented success Bitcoin suffers from many inefficiencies. For is found, it is disseminated along with the transactions that instance, Bitcoin’s consensus mechanism has been proved to the miner wishes to append.
    [Show full text]
  • 3Rd Global Cryptoasset Benchmarking Study
    3RD GLOBAL CRYPTOASSET BENCHMARKING STUDY Apolline Blandin, Dr. Gina Pieters, Yue Wu, Thomas Eisermann, Anton Dek, Sean Taylor, Damaris Njoki September 2020 supported by Disclaimer: Data for this report has been gathered primarily from online surveys. While every reasonable effort has been made to verify the accuracy of the data collected, the research team cannot exclude potential errors and omissions. This report should not be considered to provide legal or investment advice. Opinions expressed in this report reflect those of the authors and not necessarily those of their respective institutions. TABLE OF CONTENTS FOREWORDS ..................................................................................................................................................4 RESEARCH TEAM ..........................................................................................................................................6 ACKNOWLEDGEMENTS ............................................................................................................................7 EXECUTIVE SUMMARY ........................................................................................................................... 11 METHODOLOGY ........................................................................................................................................ 14 SECTION 1: INDUSTRY GROWTH INDICATORS .........................................................................17 Employment figures ..............................................................................................................................................................................................................17
    [Show full text]
  • EY Study: Initial Coin Offerings (Icos) the Class of 2017 – One Year Later
    EY study: Initial Coin Offerings (ICOs) The Class of 2017 – one year later October 19, 2018 In December 2017, we analyzed the top ICOs that represented 87% ICO funding in 2017. In that report, we found high risks of fraud, theft and major problems with the accuracy of representations made by start-ups seeking funding. In this follow-up study, we revisit the same group of companies to analyze their progress and investment return: ► The performance of ICOs from The Class of 2017 did little to inspire confidence.1 ► 86% are now below their listing2 price; 30% have lost substantially all value. Executive An investor purchasing a portfolio of The Class of 2017 ICOs on 1 January 2018 would most likely have lost 66% of their investment. ► Of the ICO start-ups we looked at from The Class of 2017, only 29% (25) have summary working products or prototypes, up by just 13% from the end of last year. Of those 25, seven companies accept payment in both traditional fiat currency (dollars) as well as ICO tokens, a decision that reduces the value of the tokens to the holders. ► There were gains among The Class of 2017, concentrated in 10 ICO tokens, most of which are in the blockchain infrastructure category. However, there is no sign that these new projects have had any success in reducing the dominance of Ethereum as the industry’s main platform. • 1 See methodology in appendix. • 2 Defined as when first available to trade on a cryptocurrency exchange. 02 ICO performance update ICOs broke out in 2017.
    [Show full text]
  • FTC Decrypting Cryptocurrency Scams Workshop Transcript
    FTC Decrypting Cryptocurrency Scams Workshop June 25, 2018 Transcript JASON ADLER: Good afternoon, everyone and welcome to the Federal Trade Commission's Decrypting Cryptocurrency Scams workshop. I'm Jason Adler. I'm the assistant director of the FDC's Midwest regional office here in Chicago. I want to thank you all for being here. And I want to thank DePaul University for hosting us. Before we get started, I just have a few housekeeping details to tick off. First, please set your mobile phones to silent. If you use them during the workshop, for example to comment about the workshop on social media, please be respectful of the others here. If you do comment on social media, feel free to use #cryptoscamsftc as a hashtag. We'll be live tweeting this event using that hashtag as well. Webcasting the event today, and it may be photographed or otherwise recorded, by participating you're agreeing that your image and anything you say may be posted at ftc.gov and on our social media sites. At the end of each panel, if we do have time, we'll try to answer audience questions. We have question cards out in the hall. Feel free to write down a question. Raise your hand and someone will collect it. And if we have time at the end of the panel, we'll ask them. We're also accepting questions on Twitter. So you can tweet a question to the FTC, so @FTC using hashtag #cryptoscamsftc. Finally, if you're here for CLE, please be sure and find Dan at the check in table.
    [Show full text]
  • On Scaling Decentralized Blockchains (A Position Paper)
    On Scaling Decentralized Blockchains (A Position Paper) Kyle Croman0;1, Christian Decker4, Ittay Eyal0;1, Adem Efe Gencer0;1, Ari Juels0;2, Ahmed Kosba0;3, Andrew Miller0;3, Prateek Saxena6, Elaine Shi0;1, Emin G¨un Sirer0;1, Dawn Song0;5, and Roger Wattenhofer4 0 Initiative for CryptoCurrencies and Contracts (IC3) 1 Cornell 2 Jacobs, Cornell Tech 3 UMD 4 ETH 5 Berkeley 6 NUS Abstract. The increasing popularity of blockchain-based cryptocurren- cies has made scalability a primary and urgent concern. We analyze how fundamental and circumstantial bottlenecks in Bitcoin limit the abil- ity of its current peer-to-peer overlay network to support substantially higher throughputs and lower latencies. Our results suggest that repa- rameterization of block size and intervals should be viewed only as a first increment toward achieving next-generation, high-load blockchain proto- cols, and major advances will additionally require a basic rethinking of technical approaches. We offer a structured perspective on the design space for such approaches. Within this perspective, we enumerate and briefly discuss a number of recently proposed protocol ideas and offer several new ideas and open challenges. 1 Introduction Increasing adoption of cryptocurrencies has raised concerns about their abil- ity to scale. Since Bitcoin is a self-regulating system that works by discovering blocks at approximate intervals, its highest transaction throughput is effectively capped at maximum block size divided by block interval. The current trend of ever increasing block sizes on Bitcoin portends a potential problem where the sys- tem will reach its maximum capacity to clear transactions, probably by 2017 [46].
    [Show full text]
  • On Scalability of Blockchain Technologies
    ON SCALABILITY OF BLOCKCHAIN TECHNOLOGIES A Dissertation Presented to the Faculty of the Graduate School of Cornell University in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy by Adem Efe Gencer August 2017 c 2017 Adem Efe Gencer ALL RIGHTS RESERVED ON SCALABILITY OF BLOCKCHAIN TECHNOLOGIES Adem Efe Gencer, Ph.D. Cornell University 2017 In this dissertation, we explore how to improve scalability of blockchains while maintaining their fundamental premise of decentralization. Scalable blockchains are capable of delivering a target throughput and latency in the presence of increasing workload. To this end, first we present Bitcoin-NG, a new blockchain protocol designed to provide scale for services involving fre- quent, high-volume interactions. This Byzantine fault tolerant blockchain pro- tocol is robust to extreme churn and shares the same trust model as Bitcoin. We experimentally demonstrate that Bitcoin-NG scales optimally, with band- width limited only by the capacity of the individual nodes and latency limited only by the propagation time of the network. Then, we examine the scalabil- ity challenges arising from proliferation of blockchain services. In particular, we observe that due to inherently single-service oriented blockchain protocols, services can bloat the existing blockchains, fail to provide sufficient security, or completely forego the property of trustless auditability. We introduce Aspen, a sharded blockchain protocol that securely scales with increasing number of services. Aspen enables service integration without compromising security — leveraging the trust assumptions — or flooding users with irrelevant messages. Finally, we provide the means to assess the viability of different scaling solu- tions. We develop and utilize custom metrics for evaluating performance and security of blockchain protocols.
    [Show full text]
  • “Satoshi Is Dead. Long Live Satoshi”: the Curious Case of Bitcoin's Creator
    “SATOSHI IS DEAD. LONG LIVE SATOSHI”: THE CURIOUS CASE OF BITCOIN’S CREATOR Mariam Humayun and Russell W. Belk ABSTRACT Purpose: In this paper, we focus on the mythic nature of the anonymous Bitcoin creator, Satoshi Nakamoto. Drawing on ideas from Foucault and Barthes on authorship, we analyze the notion of the absence of the author and how that sustains the brand. Design/methodology/approach: Based on interview data, participant obser- vation, archival data, and a netnography, we examine the discourses that emerge in the wake of multiple Satoshi Nakamoto exposés that serve as both stabilizing and destabilizing forces in the Bitcoin ecosystem. Findings: We analyze the different interpretations of Satoshi Nakamoto through his own text and how his readers interpret him. We identify how consumers employ motifs of myth and religiosity in trying to find meaning in Satoshi’s disappearance. His absence allows for multiple interpretations of how the Bitcoin brand is viewed and adopted by a diverse community of enthusiasts. Consumer Culture Theory Research in Consumer Behavior, Volume 19, 19–35 Copyright © 2018 by Emerald Publishing Limited All rights of reproduction in any form reserved ISSN: 0885-2111/doi:10.1108/S0885-211120180000019002 19 20 MARIAM HUMAYUN AND RUSSELL W. BELK Implications: Our findings provide a richer understanding of how, in a period of celebrity brands, Satoshi Nakamoto’s anti-celebrity stance helps sustain the Bitcoin ecosystem. Originality/value: Our analysis examines the nature of anonymity in our hyper-celebrity culture and the mystique of the anonymous creator that fuels modern-day myths for brands without owners. Keywords: brands; myth; anonymity; privacy; death of the author; anti-celebrity; religiosity; bitcoin; blockchain; Satoshi Nakamoto A legend has emerged from a jumble of facts: Someone using the name Satoshi Nakamoto released the software for Bitcoin in early 2009 and communicated with the nascent cur- rency’s users via email — but never by phone or in person.
    [Show full text]
  • In Re Ripple Labs Inc. Litigation 18-CV-06753-Consolidated
    Case 4:18-cv-06753-PJH Document 63 Filed 08/05/19 Page 1 of 53 1 James Q. Taylor-Copeland (284743) [email protected] 2 TAYLOR-COPELAND LAW 501 W. Broadway, Suite 800 3 San Diego, CA 92101 Telephone: (619) 400-4944 4 Facsimile: (619) 566-4341 5 Marc M. Seltzer (54534) [email protected] 6 Steven G. Sklaver (237612) [email protected] 7 Oleg Elkhunovich (269238) [email protected] 8 Meng Xi (280099) [email protected] 9 SUSMAN GODFREY L.L.P. 1900 Avenue of the Stars, 14th Floor 10 Los Angeles, CA 90067 Telephone: (310) 789-3100 11 Facsimile: (310) 789-3150 12 Counsel for Lead Plaintiff Bradley Sostack 13 UNITED STATES DISTRICT COURT 14 NORTHERN DISTRICT OF CALIFORNIA 15 OAKLAND DIVISION 16 ) Case No. 4:18-cv-06753-PJH 17 In re RIPPLE LABS INC. LITIGATION, ) ) CLASS ACTION 18 ____________________________________ ) ) CONSOLIDATED COMPLAINT FOR 19 This Document Relates To: ) VIOLATIONS OF FEDERAL AND ) CALIFORNIA LAW 20 ALL ACTIONS ) ) 21 ) JURY TRIAL DEMANDED 22 23 24 25 26 27 28 CONSOLIDATED COMPLAINT Case 4:18-cv-06753-PJH Document 63 Filed 08/05/19 Page 2 of 53 1 TABLE OF CONTENTS 2 SUMMARY OF ACTION ...................................................................................................2 3 PARTIES .............................................................................................................................6 4 JURISDICTION AND VENUE ..........................................................................................6 5 SUBSTANTIVE ALLEGATIONS .....................................................................................7
    [Show full text]
  • Proof of Activity: Extending Bitcoin's Proof of Work Via Proof of Stake
    Proof of Activity: Extending Bitcoin's Proof of Work via Proof of Stake Iddo Bentov∗ Charles Lee Alex Mizrahi Meni Rosenfeld Computer Science Dept., Technion Litecoin Project chromawallet.com Israeli Bitcoin Association [email protected] [email protected] [email protected] [email protected] Abstract We propose a new protocol for a cryptocurrency, that builds upon the Bitcoin protocol by combining its Proof of Work component with a Proof of Stake type of system. Our Proof of Activity (PoA) protocol offers good security against possibly practical future attacks on Bitcoin, and has a relatively low penalty in terms of network communication and storage space. We explore various attack scenarios and suggest remedies to potential vulnerabilities of the PoA protocol, as well as evaluate the performance of its core subroutine. 1 Introduction The Bitcoin [33] cryptocurrency continues to gather success since its launch in 2009. As a means of exchange, Bitcoin facilitates fast worldwide transactions with trivial fees and without identity theft risks. As a store of value, Bitcoin entails no counterparty risk and no exposure to manipulation of the money supply by central banks, due to its decentralized nature. Many other features can be derived from Bitcoin's cryptographic foundations, including: resilient forms of secret sharing via multi-signature control over an address [13, 18], non-interactive transactions with other systems via computational integrity proofs [29], off-chain micropay- ment channels [20,36], various types of contracts that are enforced by the distributed network [18], trust-free gambling and multiparty computation [1,2,4], trust-free sale of computed data via zero-knowledge proofs [24], hierarchical wallets that use key homomorphism to minimize access to the private keys [26], decentralized stock exchange and prediction market via colored coins [12, 32], and so on.
    [Show full text]
  • From Hodl to Heist: Analysis of Cyber Security Threats to Bitcoin Exchanges
    From Hodl to Heist: Analysis of Cyber Security Threats to Bitcoin Exchanges Kris Oosthoek Christian Doerr Cyber Threat Intelligence Lab Cyber Threat Intelligence Lab Delft University of Technology Delft University of Technology Delft, The Netherlands Delft, The Netherlands [email protected] [email protected] Abstract—Bitcoin is gaining traction as an alternative store of A high value asset makes a high value attack target. The value. Its market capitalization transcends all other cryptocur- security of Bitcoin is also dependent on the ecosystem that rencies in the market. But its high monetary value also makes it has emerged around it. This consists of exchange platforms, an attractive target to cyber criminal actors. Hacking campaigns usually target the weakest points in an ecosystem. In Bitcoin, payment service providers, wallet providers, mining pools and these are currently the exchange platforms. As each exchange other intermediaries. Each of these is part of a fabric spun breach potentially decreases Bitcoin’s market value by billions, around Bitcoin which unlocks its potential to a broader user it is a threat not only to direct victims, but to everyone owning base, but consequently introduces additional threat vectors. Bitcoin. Based on an extensive analysis of 36 breaches of Bitcoin Cyber criminal actors generally target the weakest points in exchanges, we show the attack patterns used to exploit Bitcoin exchange platforms using an industry standard for reporting the ecosystem. In the Bitcoin ecosystem, these are currently intelligence on cyber security breaches. Based on this we are the centralized exchanges. These act as a broker, allowing able to provide an overview of the most common attack vectors, users to sell cryptocurrencies for fiat currency (legal tender) showing that all except three hacks were possible due to relatively or to exchange the latter for cryptocurrency against a commis- lax security.
    [Show full text]