Monero (/məˈnɛroʊ/; Abbreviation: XMR) is a cryptocurrency which uses a blockchain with privacy-enhancing technologies to obfuscate transactions to achieve anonymity and fungibility.

The Monero protocol includes various methods to obfuscate transaction details, though users can optionally share view keys for third-party auditing.

"[4] Due to its perceived untraceability Monero is gaining increased use in illicit activities such as money laundering, darknet markets, ransomware, cryptojacking, and other organized crime.

The United States Internal Revenue Service (IRS) has posted bounties for contractors that can develop Monero tracing technologies.

[5] Monero's roots trace back to CryptoNote v2, a cryptocurrency protocol first introduced in a white paper published by the presumed pseudonymous Nicolas van Saberhagen in October 2013.

[6] In the paper, the author described privacy and anonymity as "the most important aspects of electronic cash" and characterized bitcoin's traceability as a "critical flaw".

Finally, "Temporal Analysis", shows that predicting the right output in a ring signature could potentially be easier than previously thought.

[17] In September 2020, the United States Internal Revenue Service's criminal investigation division (IRS-CI), posted a $625,000 bounty for contractors who could develop tools to help trace Monero, other privacy-enhanced cryptocurrencies, the Bitcoin Lightning Network, or other "layer 2" protocol.

[11][23][24] After many online payment platforms shut down access for white nationalists following the Unite the Right rally in 2017, some of them, including Christopher Cantwell and Andrew Auernheimer ("weev"), started using and promoting Monero.

[8][29] In late 2017, malware and antivirus service providers blocked Coinhive, a JavaScript implementation of a Monero miner that was embedded in websites and apps, in some cases by hackers.

[36] The perpetrators of the 2017 WannaCry ransomware attack, which was attributed by the US government to North Korean threat actors,[37] attempted to exchange the ransom they collected in Bitcoin to Monero.

[38] In 2021, CNBC, the Financial Times, and Newsweek reported that demand for Monero was increasing following the recovery of a bitcoin ransom paid in the Colonial Pipeline cyber attack.

[9][7][40] The May 2021 hack forced the pipeline to pay a $4.4M ransom in bitcoin, though a large portion was recovered by the United States federal government the following month.

[7] Despite this, CNBC reported that bitcoin was still the currency of choice demanded in most ransomware attacks, as insurers refuse to pay Monero ransom payments because of traceability concerns.

[41] In 2018, Europol and its director Rob Wainwright wrote that the year would see criminals shift from using bitcoin to using Monero, as well as Ethereum, Dash, and Zcash.