:Bram Cohen

Cohen grew up on the Upper West Side of Manhattan, New York City, as the son of a teacher and computer scientist. He claims he learned the BASIC programming language at the age of 5 on his family's Timex Sinclair computer. Cohen passed the American Invitational Mathematics Examination to qualify for the United States of America Mathematical Olympiad while he attended Stuyvesant High School in New York City. He graduated from Stuyvesant in 1993,{{cite web |last=Cohen |first=Bram |title=Résumé |work=BitConjurer.org |url= http://bitconjurer.org/resume.txt |archive-url= https://web.archive.org/web/20110708090755/http://bramcohen.com/resume.txt |archive-date=July 8, 2011 |access-date=April 3, 2014}} {{Self-published source|certain=y|date=May 2025|ABOUTSELF=y}} and attended SUNY Buffalo. He later dropped out of college to work for several dot-com companies throughout the mid-to-late 1990s, the last being MojoNation, an ambitious but ill-fated project he worked on with Jim McCoy.

MojoNation allowed people to break up confidential files into encrypted chunks and distribute those pieces on computers also running the software. If someone wanted to download a copy of this encrypted file, they would have to download it simultaneously from many computers. This concept, Cohen thought, was perfect for a file-sharing program, since programs like KaZaA take a long time to download a large file because the file is (usually) coming from one source (or peer).

In April 2001, Cohen quit MojoNation and began work on BitTorrent. Cohen designed BitTorrent to be able to download files from many sources, thus speeding up the download time, especially for users with faster download than upload speeds. Thus, the more popular a file is, the faster a user will be able to download it, since many people will be downloading it at the same time, and these people will also be uploading the data to other users. Cohen unveiled his ideas at the first CodeCon conference, which he and his roommate Len Sassaman created as a showcase event for novel technology projects after becoming disillusioned with the state of then-current technology conferences.

Cohen wrote the first BitTorrent client implementation in Python. In the summer of 2002, Cohen collected free pornography to lure beta testers to use the program.{{cite magazine |last=Thompson |first=Clive |title=The BitTorrent Effect |work=Wired |date=January 2005 |url= https://www.wired.com/wired/archive/13.01/bittorrent.html |url-status=live |access-date=March 18, 2006 |archive-url= https://web.archive.org/web/20060326210400/http://www.wired.com/wired/archive/13.01/bittorrent.html |archive-date=March 26, 2006}} In May 2005, Cohen released a trackerless beta version of BitTorrent. BitTorrent gained its fame for its ability to quickly share large music and movie files online. Since the early releases, many other programs have implemented the BitTorrent protocol.

Cohen has claimed he has never violated copyright law using his software. Regardless, he is outspoken in his belief that the traditional media business model is doomed to becoming outmoded, despite RIAA's and MPAA's legal and technical tactics, such as digital rights management.

In late 2003, Cohen worked for a short time at Valve, working on Steam, their digital distribution system introduced for Half-Life 2.{{citation needed|date=November 2019}}

By 2004, he had left Valve and formed BitTorrent, Inc., with his brother Ross Cohen and business partner Ashwin Navin. In 2012, he announced a beta version of BitTorrent Live for TV broadcasting through the Internet.{{cite web |author= |title=BitTorrent Live JukeBox |work=BitTorrent Live Beta |publisher=BitTorrent, Inc. |date=2011 |url= http://live.bittorrent.com/ |url-status=dead |archive-url= https://web.archive.org/web/20131025133454/http://live.bittorrent.com/ |archive-date=October 25, 2013}} Cohen left BitTorrent, Inc., in a day-to-day capacity to co-found Chia Network in the fall of 2017.{{cite web |last=Constine |first=Josh |title=BitTorrent inventor announces eco-friendly Bitcoin competitor Chia |date=November 8, 2017 |publisher=TechCrunch |url= https://techcrunch.com/2017/11/08/chia-network-cryptocurrency/ |url-status=live |access-date=January 18, 2018 |archive-url= https://web.archive.org/web/20180126230245/https://techcrunch.com/2017/11/08/chia-network-cryptocurrency/ |archive-date=January 26, 2018}}

By mid-2005, BitTorrent, Inc., was funded by venture capitalist David Chao from Doll Capital Management, and in late 2005 Cohen and Navin made a deal with the MPAA to remove links to illegal content on the official BitTorrent website. The deal was with the seven largest studios in the United States. The agreement means the site will comply with procedures outlined in the Digital Millennium Copyright Act.{{cite magazine |title=Hollywood Hopes BitTorrent Deal Will Reduce Illegal Movie Downloads |first=Gary |last=Gentile |date=November 23, 2005 |work=InformationWeek |url= http://www.informationweek.com/story/showArticle.jhtml?articleID=174401655}}{{dead link|date=November 2016 |bot=InternetArchiveBot |fix-attempted=yes }}

{{anchor|Chia}}

Chia Network is a company founded by Cohen in 2017 that has implemented a proof-of-space-time cryptocurrency called Chia (XCH). Chia is intended to avoid the waste of energy involved in proof-of-work-based cryptocurrencies such as Bitcoin,{{Cite web |title=Energy-saving Bitcoin rival Chia raises from A16Z, plans mini-IPO |work=TechCrunch |date=March 28, 2018 |url= https://techcrunch.com/2018/03/28/chia-vs-bitcoin/ |url-status=live |access-date=February 15, 2021 |archive-url= https://web.archive.org/web/20210213002026/https://techcrunch.com/2018/03/28/chia-vs-bitcoin/ |archive-date=February 13, 2021}} and the vulnerability to state actors of proof-of-stake systems.

Chia Network has raised seed money from investors including Andreessen Horowitz. The use of storage media (hard disks and solid-state drives) as the cryptocurrency's mining medium has raised concerns over potential price surges and shortage of high-capacity storage devices,{{cite magazine |last=Humphries |first=Matthew |title=Chia Cryptocurrency Expected to Cause Hard Drive and SSD Shortages |work=PC Magazine |date=April 19, 2021 |url= https://www.pcmag.com/news/chia-cryptocurrency-expected-to-cause-hard-drive-and-ssd-shortages |url-status=live |access-date=May 10, 2021 |archive-url= https://web.archive.org/web/20210510171721/https://www.pcmag.com/news/chia-cryptocurrency-expected-to-cause-hard-drive-and-ssd-shortages |archive-date=May 10, 2021}} as well as radically reducing the lifetime of drives.{{Cite magazine |last=Lilly |first=Paul |title=Chia mining can wreck a 512GB SSD in as little as 6 weeks |work=PC Gamer |date=May 11, 2021 |url= https://www.pcgamer.com/chia-mining-can-wreck-a-512gb-ssd-in-as-little-as-6-weeks/ |url-status=live |access-date=May 19, 2021 |archive-url= https://web.archive.org/web/20210517212000/https://www.pcgamer.com/chia-mining-can-wreck-a-512gb-ssd-in-as-little-as-6-weeks/ |archive-date=May 17, 2021}}

As of 2008, Cohen lived in the San Francisco Bay Area of the United States, with his wife Jenna and their three children.{{cite magazine |last=Berfield |first=Susan |title=BitTorrent's Bram Cohen Isn't Limited by Asperger's |work=Bloomberg Businessweek |publisher=Bloomberg L.P |date=October 15, 2008 |url= https://www.bloomberg.com/news/articles/2008-10-15/bittorrents-bram-cohen-isnt-limited-by-aspergers |access-date=March 22, 2016 |url-status=live |archive-url= https://web.archive.org/web/20170522203141/https://www.bloomberg.com/news/articles/2008-10-15/bittorrents-bram-cohen-isnt-limited-by-aspergers |archive-date=May 22, 2017}} The couple divorced in 2022.{{cite web |title=Case Number: FDI17788802Title: Bram Cohen vs. Jenna Leigh Cohen; Cause of Action: Petition for Dissolution with Children |work=WebApps.SFTC.org |publisher=Superior Court of California, County of San Francisco |date=December 9, 2022 |url= https://webapps.sftc.org/ci/CaseInfo.dll?CaseNum=FDI17788802 |access-date=May 3, 2025 |quote=Judgment, Dissolution of Marriage, Marital Status Ends Dec-08-2022; Notice of Entry of Judgment, Dissolution of Marriage}}

Cohen says that he has Asperger syndrome based on a self diagnosis.{{cite magazine |last=Roth |first=Daniel |title=Torrential Reign |date=November 14, 2005 |work=Fortune |pages=91–96 |url= https://money.cnn.com/magazines/fortune/fortune_archive/2005/10/31/8359146/index.htm |url-status=live |access-date=November 6, 2006 |archive-url= https://web.archive.org/web/20060408184548/http://money.cnn.com/magazines/fortune/fortune_archive/2005/10/31/8359146/index.htm |archive-date=April 8, 2006}}

Cohen's hobbies include original origami and juggling up to five balls, but his main interest is in recreational mathematics. Cohen maintains a blog{{Cite web |last=Cohen |first=Bram |title=Bram Cohen's Journal |work=BramCohen.LiveJournal.com |url= https://bramcohen.livejournal.com/ |access-date=September 24, 2022}} {{Self-published source|certain=y|date=May 2025|ABOUTSELF=y}} where he frequently discusses trust metrics with software developer Raph Levien, as well as money systems, games of skill, and other math-related topics. He is also an assembly puzzle enthusiast.{{cite web |last=Cohen |first=Bram |title=TCP Sucks |work=Bram Cohen's Blog |access-date=September 7, 2012 |date=May 7, 2012 |url= http://bramcohen.com/ |url-status=live |archive-url= https://web.archive.org/web/20151216151943/http://bramcohen.com/ |archive-date=December 16, 2015}} {{Self-published source|certain=y|date=May 2025|ABOUTSELF=y}}{{cite web |last=McIntosh |first=Jason |title=Bram Cohen's puzzle shop |date=June 21, 2009 |work=The Gameshelf |url= http://gameshelf.jmac.org/2009/06/bram-cohens-puzzle-shop/ |access-date=September 7, 2012 |archive-date=January 11, 2012 |archive-url= https://web.archive.org/web/20120111124903/http://gameshelf.jmac.org/2009/06/bram-cohens-puzzle-shop/ |url-status=live}} He has designed several puzzles including some in conjunction with Oskar van Deventer including several gear-based puzzles such as Gear Shift{{cite web |last=van Deventer |first=Oskar |author-link=Oskar van Deventer |title=Gear Shift |publisher=YouTube |access-date=May 14, 2013 |date=October 9, 2010 |url= https://www.youtube.com/watch?v=PkAlP9W0PM0 |url-status=live |archive-url= https://web.archive.org/web/20160704091558/https://www.youtube.com/watch?v=PkAlP9W0PM0 |archive-date=July 4, 2016}} and a multiple Rubik's Cube variant called Bram's Fortress.{{cite web |last=van Deventer |first=Oskar |author-link=Oskar van Deventer |title=Bram's Fortress |publisher=YouTube |date=August 25, 2012 |url= https://www.youtube.com/watch?v=WeV-LBIzjJ4 |url-status=live |access-date=May 14, 2013 |archive-url= https://web.archive.org/web/20161013164529/https://www.youtube.com/watch?v=WeV-LBIzjJ4 |archive-date=October 13, 2016}} Some of Cohen's puzzle designs are available for 3-D printing via Shapeways.{{cite web |last=Cohen |first=Bram |title=Bram Cohen Puzzles |date=August 25, 2012 |work=Shapeways.com |url= http://www.shapeways.com/shops/bram_cohen |url-status=live |access-date=May 14, 2013 |archive-url= https://web.archive.org/web/20131116040922/http://www.shapeways.com/shops/bram_cohen |archive-date=November 16, 2013}}

Cohen has received a number of awards for his work on the BitTorrent protocol, including:

• 2004 Wired Rave Award{{cite magazine |title=The 2004 Wired Rave Awards |work=Wired |volume=12 |issue=4 |date=January 4, 2009 |access-date=November 11, 2011 |url= https://www.wired.com/wired/archive/12.04/rave.html?pg=10 |url-status=live |archive-url= https://web.archive.org/web/20120527113610/http://www.wired.com/wired/archive/12.04/rave.html?pg=10 |archive-date=May 27, 2012}}
• 2005 MIT Technology Review TR35 as one of the top 35 innovators in the world under the age of 35{{cite journal |title=2005 Young Innovators Under 35: Bram Cohen, 29 |work=MIT Technology Review |date=2005 |url= http://www.technologyreview.com/tr35/profile.aspx?TRID=93 |url-status=live |access-date=August 14, 2011 |archive-url= https://web.archive.org/web/20120128071326/http://www.technologyreview.com/tr35/profile.aspx?trid=93 |archive-date=January 28, 2012}}
• 2005 Time{{'s}} 100 Most Influential People{{cite magazine |title=Special Issue: The Time 100 |work=Time |date=April 10, 2005 |url= http://www.time.com/time/press_releases/article/0,8599,1047355,00.html |access-date=July 14, 2010 |archive-url= https://web.archive.org/web/20121105171052/http://www.time.com/time/press_releases/article/0,8599,1047355,00.html |archive-date=November 5, 2012}}
• 2006 USENIX STUG Award{{cite web |title=Usenix Stug Award |publisher=USENIX |url= http://www.usenix.org/about/stug.html |url-status=live |access-date=November 11, 2011 |archive-url= https://web.archive.org/web/20120111115607/http://www.usenix.org/about/stug.html |archive-date=January 11, 2012}}
• 2010 Internet Evolution 100{{cite web |title=The Big Report – The Internet Evolution 100 |publisher=Internet Evolution |url= http://www.internetevolution.com/document.asp?doc_id=190304 |access-date=November 11, 2011 |archive-url= https://web.archive.org/web/20130831150756/http://www.internetevolution.com/document.asp?doc_id=190304 |archive-date=August 31, 2013}}

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• {{Official website|https://bramcohen.com/}}

{{BitTorrent}}

{{Cryptocurrencies}}

{{Authority control}}

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