A cryptocurrency tumbler or cryptocurrency mixing service [1] is a service that mixes potentially identifiable or "tainted" cryptocurrency funds with others, so as to obscure the trail back to the fund's original source. [2] This is usually done by pooling together source funds from multiple inputs for a large and random period of time, and then spitting them back out to destination addresses. As all the funds are lumped together and then distributed at random times, it is very difficult to trace exact coins. Tumblers have arisen to improve the anonymity of cryptocurrencies, usually bitcoin (hence bitcoin mixer), since the digital currencies provide a public ledger of all transactions. Due to its goal of anonymity, tumblers have been used to money launder cryptocurrency.
Tumblers take a percentage transaction fee of the total coins mixed to turn a profit, typically 1–3%. [3] Mixing helps protect privacy and can also be used for money laundering by mixing illegally obtained funds. Mixing large amounts of money may be illegal, being in violation of anti-structuring laws. Financial crimes author Jeffrey Robinson has suggested tumblers should be criminalized due to their potential use in illegal activities, specifically funding terrorism; [3] however, a report from the CTC suggests such use in terrorism-related activities is "relatively limited". [4] There has been at least one incident where an exchange has blacklisted "tainted" deposits descending from stolen bitcoins.[ citation needed ]
The existence of tumblers has made the anonymous use of darknet markets easier and the job of law enforcement harder. [5]
Peer-to-peer tumblers act as a place of meeting for bitcoin users, instead of taking bitcoins for mixing. Users arrange mixing by themselves. This model solves the problem of stealing, as there is no middleman. When it is completely formed, the exchange of bitcoins between the participants begins. Apart from mixing server, none of the participants can know the connection between the incoming and outgoing addresses of coins. [6]
In December 2013 cryptocurrency tumbler Bitcoin Fog [7] was used to launder a part of the 96,000 BTC from the robbery of Sheep Marketplace. [8]
In February 2015, a total of 7,170 Bitcoin was stolen from the Chinese exchange Bter.com and traced back to the same tumbler. [9]
In May 2019, FinCEN published a Guidance document that mentioned anonymizing services and mentioned particularly "tumblers". [10]
In February 2020, the alleged operator of a cryptocurrency tumbler was indicted on charges of "money laundering conspiracy, operating an unlicensed money transmitting business and conducting money transmission without a D.C. license." [11]
In January 2021, the Department of Justice conducted an operation targeting the ransomware hacker NetWalker, successfully confiscating around $500,000 in digital assets. Then, in February 2021, they apprehended three hackers affiliated with the North Korean military, recovering $2 million in illicitly acquired digital assets. [12]
In April 2021, U.S. Federal authorities arrested the founder of Bitcoin Fog, a Russian-Swedish man named Roman Sterlingov, on charges of money laundering, operating an unlicensed money transmitting business, and money transmission without a license in the District of Columbia. It was alleged that during its 10 years of operation, Bitcoin Fog laundered over 1.2 million Bitcoin at a value of approximately $335 million. [13] [14] In March 2024 the verdict came back guilty on all counts. Roman's counsel plan to appeal the verdict. Sentencing is set for July 2024. [15]
In 2022 the tumblers Blender.io and Tornado Cash were both sanctioned by the United States Department of the Treasury, making it illegal for US citizens, residents and companies to use the service. [16] [17]
In March 2023, the tumbler ChipMixer and 46 million dollars in Bitcoin were seized. [18]
Money laundering is the process of illegally concealing the origin of money, obtained from illicit activities such as drug trafficking, corruption, embezzlement or gambling, by converting it into a legitimate source. It is a crime in many jurisdictions with varying definitions. It is usually a key operation of organized crime.
A cryptocurrency exchange, or a digital currency exchange (DCE), is a business that allows customers to trade cryptocurrencies or digital currencies for other assets, such as conventional fiat money or other digital currencies. Exchanges may accept credit card payments, wire transfers or other forms of payment in exchange for digital currencies or cryptocurrencies. A cryptocurrency exchange can be a market maker that typically takes the bid–ask spreads as a transaction commission for its service or, as a matching platform, simply charges fees.
A cryptocurrency, crypto-currency, or crypto is a digital currency designed to work as a medium of exchange through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it.
Bitstamp is a European cryptocurrency exchange founded in 2011. It is the world’s longest-running cryptocurrency exchange. It allows trading between fiat currency, Bitcoin and other cryptocurrencies, such as USD, EUR, GBP, Ethereum, Litecoin, Ripple, Bitcoin Cash, Algorand, Stellar, and USD Coin. Business operations are conducted from its registered headquarters in Luxembourg City, with a satellite office in Ljubljana.
The dark web is the World Wide Web content that exists on darknets: overlay networks that use the Internet but require specific software, configurations, or authorization to access. Through the dark web, private computer networks can communicate and conduct business anonymously without divulging identifying information, such as a user's location. The dark web forms a small part of the deep web, the part of the web not indexed by web search engines, although sometimes the term deep web is mistakenly used to refer specifically to the dark web.
Sheep Marketplace was an anonymous marketplace set up as a Tor hidden service. It launched in March 2013 and was one of the lesser known sites to gain popularity with the well publicized closure of the Silk Road marketplace later that year. It ceased operation in December 2013, when it announced it was shutting down after a vendor stole $6 million worth of users' bitcoins.
A Bitcoin ATM is a kiosk that allows a person to purchase Bitcoin and other cryptocurrencies by using cash or debit card. Some Bitcoin ATMs offer bidirectional functionality, enabling both the purchase of Bitcoin and the sale of Bitcoin for cash. In some cases, Bitcoin ATM providers require users to have an existing account to transact on the machine.
Monero is a cryptocurrency which uses a blockchain with privacy-enhancing technologies to obfuscate transactions to achieve anonymity and fungibility. Observers cannot decipher addresses trading Monero, transaction amounts, address balances, or transaction histories.
A darknet market is a commercial website on the dark web that operates via darknets such as Tor and I2P. They function primarily as black markets, selling or brokering transactions involving drugs, cyber-arms, weapons, counterfeit currency, stolen credit card details, forged documents, unlicensed pharmaceuticals, steroids, and other illicit goods as well as the sale of legal products. In December 2014, a study by Gareth Owen from the University of Portsmouth suggested the second most popular sites on Tor were darknet markets.
DeepDotWeb was a news site dedicated to events in and surrounding the dark web featuring interviews and reviews about darknet markets, Tor hidden services, privacy, bitcoin, and related news. The website was seized on May 7, 2019, during an investigation into the owners' affiliate marketing model, in which they received money for posting links to certain darknet markets, and for which they were charged with conspiracy to commit money laundering. In March 2021 site administrator Tal Prihar pleaded guilty to his charge of conspiracy to commit money laundering.
Grams is a discontinued search engine for Tor based darknet markets launched in April 2014, and closed in December 2017. The service allowed users to search multiple darknet markets for products like drugs and guns from a simple search interface, and also provided the capability for its users to hide their transactions through its bitcoin tumbler Helix.
An exit scam, is a confidence trick, con job or fraud, perpetuated under the guise of a legitimate business, that ends when the originator absconds with the funds contributed by participants. When a business entity rug-pulls and stops shipping orders while receiving payment for new orders, it could take some time before it is widely recognized that orders are not shipping. The entity can then make off with the money paid for unshipped orders. Customers who trusted the business do not realize that orders are not being fulfilled until the business has already disappeared. Exit scams are commonly associated with the rise of cryptocurrency projects due to the lack of regulation and decentralized ecosystem.
Bitfinex is a cryptocurrency exchange owned and operated by iFinex Inc, and is registered in the British Virgin Islands. Bitfinex was founded in 2012. It was originally a peer-to-peer Bitcoin exchange, and later added support for other cryptocurrencies.
Binance Holdings Ltd., branded Binance, is a global company that operates the largest cryptocurrency exchange in terms of daily trading volume of cryptocurrencies. Binance was founded in 2017 by Changpeng Zhao, a developer who had previously created high-frequency trading software. Binance was initially based in China, then moved to Japan shortly before the Chinese government restricted cryptocurrency companies. Binance subsequently left Japan for Malta and currently has no official company headquarters.
Cryptocurrency and crime describe notable examples of cybercrime related to theft of cryptocurrencies and some methods or security vulnerabilities commonly exploited. Cryptojacking is a form of cybercrime specific to cryptocurrencies that have been used on websites to hijack a victim's resources and use them for hashing and mining cryptocurrency.
A blockchain is a shared database that records transactions between two parties in an immutable ledger. Blockchain documents and confirms pseudonymous ownership of all transactions in a verifiable and sustainable way. After a transaction is validated and cryptographically verified by other participants or nodes in the network, it is made into a "block" on the blockchain. A block contains information about the time the transaction occurred, previous transactions, and details about the transaction. Once recorded as a block, transactions are ordered chronologically and cannot be altered. This technology rose to popularity after the creation of Bitcoin, the first application of blockchain technology, which has since catalyzed other cryptocurrencies and applications.
The Bitfinex cryptocurrency exchange was hacked in August 2016. 119,756 bitcoin, worth about US$72 million at the time, was stolen.
Hydra was a Russian language dark web marketplace, founded in 2015, that facilitated trafficking of illegal drugs, financial services including cryptocurrency tumbling for money laundering, exchange services between cryptocurrency and Russian rubles, and the sale of falsified documents and hacking services. On April 5, 2022, American and German federal government law enforcement agencies announced the seizure of the website's Germany-based servers and cryptocurrency assets. Before its closure, it had been the longest-running dark web marketplace. The United States Department of Justice has indicted one Russian man for his role in running the servers for the website.
Chainalysis is an American blockchain analysis firm headquartered in New York City. The company was co-founded by Michael Gronager, Jan Møller and Jonathan Levin in 2014, and is the first start-up company dedicated to the business of Bitcoin tracing. It offers compliance and investigation software to analyze the blockchain public ledger, which is primarily used to track virtual currencies. Next to banks and brokers its customers have included the United States Federal Bureau of Investigation, Drug Enforcement Administration, and the Internal Revenue Service Criminal Investigation, as well as the United Kingdom's National Crime Agency.
Tornado Cash is an open source, non-custodial, fully decentralized cryptocurrency tumbler that runs on Ethereum Virtual Machine-compatible networks. It offers a service that mixes potentially identifiable or "tainted" cryptocurrency funds with others, so as to obscure the trail back to the fund's original source. This is a privacy tool used in EVM networks where all transactions are public by default.
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