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Namecoin Logo
Symbol[citation needed]
Original author(s)Vincent Durham
Initial release18 April 2011 (13 years ago) (2011-04-18)[1]
Latest release0.21.0[2] / 29 January 2021 (3 years ago) (2021-01-29)
Code repository
Development statusActive
Project fork ofBitcoin
Ledger start17 April 2011 (13 years ago) (2011-04-17)[3]
Timestamping schemeProof-of-work (merged mining)[4]
Hash functionSHA-256
Block time10 minutes[5]
Supply limit21,000,000[5]

Namecoin (Abbreviation: NMC; sign: ) is a cryptocurrency originally forked from bitcoin software. It uses proof-of-work algorithm. Like bitcoin, it is limited to 21 million coins.[5]

Namecoin can store data within its own blockchain transaction database. The original proposal for Namecoin called for Namecoin to insert data into bitcoin's blockchain directly. Anticipating scaling difficulties with this approach, a shared proof-of-work system was proposed to secure new cryptocurrencies with different use cases.

Namecoin's flagship use case is the censorship-resistant top level domain .bit, which is functionally similar to .com or .net domains but is independent of the Internet Corporation for Assigned Names and Numbers, the main governing body for domain names.[6] In practice, the top level domain is used by a handful of functional websites. As of 2019, OpenNIC no longer supports the .bit domain.


A peer-to-peer network similar to handles Namecoin's transactions, balances and issuance through a based proof-of-work scheme (they are issued when a small enough hash value is found, at which point a block is created).[7]


Each Namecoin record consists of a name and a value. Each name is actually a path, with the namespace preceding the name of the record. The key d/example signifies a record stored in the DNS namespace d with the name example and corresponds to the record for the example.bit website. The content of d/example is expected to conform to the DNS namespace specification. As of 2015, the fee for a record was 0.01 NMC and records expired after 36000 blocks (~200 days) unless updated or renewed.[7]


.bit is a top-level domain, created outside the commonly used Domain Name System, and is not sanctioned by ICANN. The .bit domain is served via Namecoin infrastructure, which acts as a decentralized domain name system.[7]

Proposed potential uses for Namecoin besides domain name registration include notary/timestamp systems.[8]


In September 2010, a discussion was started[by whom?] in the BitcoinTalk forum about a hypothetical system called BitDNS and generalizing bitcoin. Gavin Andresen and Satoshi Nakamoto joined the discussion in the BitcoinTalk forum and supported the idea of BitDNS, and a reward for implementing BitDNS was announced on the forum in December 2010.[citation needed]

On block 19200 Namecoin activated the merged mining upgrade to allow mining of Bitcoin and Namecoin simultaneously, instead of having to choose between one or the other; this fixed the issue of miners jumping from one blockchain to another when the profitability becomes favorable in the former.[4]

Two years later, in June 2013, NameID was launched.[9] NameID allows to associate profile information with identities on the Namecoin blockchain, and an OpenID provider to allow logging into existing websites with Namecoin identities. The main site itself is accompanied by an open protocol for password-less authentication with Namecoin identities, a corresponding free-software implementation and a supporting extension for Firefox.[citation needed]

In October 2013, Michael Gronager, main developer of libcoin, found a security issue in the Namecoin protocol, which allowed modifying foreign names. It was successfully fixed in a short timeframe and was never exploited, except for bitcoin.bit as a proof-of-concept.[10][citation needed]

Namecoin was also mentioned by ICANN in a public report as the most well-known example of distributing control and privacy in DNS.[11]

A 2015 study found that of the 120,000 domain names registered on Namecoin, only 28 were in use.[7]

In December 2018, a proposal was tabled on the OpenNIC mailing list to drop support for Namecoin .bit domains.,[12] citing Spamhaus' (and by extension other antivirus software) blocking of several of their servers owing to spread of malware from some .bit domains, as well as concerns about potential child pornography. The vote did not reach a consensus.[13]

In the same month, OpenNIC was advised to drop support for .bit namespace owing to security concerns of Namecoin and PRISM Break developers.[14]

In July 2019, OpenNIC again voted on dropping the .bit namespace, citing "numerous problems with support of NameCoin domains" and recent animosity between the two projects. The vote passed.[15] Namecoin developer Jeremy Rand welcomed the move, thanking OpenNIC and describing it as the "right decision".[16][17][18]

See also


  1. ^ "[announce] Namecoin - a distributed naming system based on Bitcoin".
  2. ^ "Releases - namecoin/namecoin-core". Archived from the original on 2020-11-09. Retrieved 2021-03-03 – via GitHub.
  3. ^ "Block #0". Archived from the original on 2021-08-02. Retrieved 2021-03-03.
  4. ^ a b "Merged Mining: Analysis of Effects and Implications". Archived from the original on 2020-11-11. Retrieved 2018-12-24.
  5. ^ a b c Loibl, Andreas (2014-08-01). "Namecoin" (PDF). Archived (PDF) from the original on 2022-05-18. Retrieved 2020-11-26.
  6. ^ Dourado, Eli (2014-02-05). "Can Namecoin Obsolete ICANN (and More)?". Theumlaut. Archived from the original on 2020-11-12. Retrieved 2020-11-26.
  7. ^ a b c d Kalodner, Harry; Carlsten, Miles; Ellenbogen, Paul; Bonneau, Joseph; Narayanan, Arvind (2015). "An empirical study of Namecoin and lessons for decentralized namespace design" (PDF). Workshop on the Economics of Information Security. CiteSeerX Archived (PDF) from the original on 2022-11-10. Retrieved 2022-11-10.
  8. ^ Kirk, Jeremy (2013-05-24). "Could the Bitcoin network be used as an ultrasecure notary service?". Techworld. Archived from the original on 2014-10-12. Retrieved 2013-07-02.
  9. ^ Kraft, Daniel (2013-07-25). "NameID - Use namecoin id/ to log into OpenID sites". Namecoin Forum. Archived from the original on 2015-05-14. Retrieved 2015-10-14.
  10. ^ bitcoin.bit name operation is in tx-id 2f034f2499c136a2c5a922ca4be65c1292815c753bbb100a2a26d5ad532c3919
  11. ^ "The Internet Corporation for Assigned Names and Numbers Identifier Technology Innovation Report" (PDF). ICANN. 2014-05-15. Archived (PDF) from the original on 2021-12-19. Retrieved 2021-10-17.
  12. ^ "Should we have a vote on .bit ?". opennic-discuss. Archived from the original on 2021-01-27. Retrieved 2021-03-02.
  13. ^ "Vote to keep or drop peering with NameCoin". opennic-discuss. Archived from the original on 2022-04-16. Retrieved 2021-03-02.
  14. ^ "Drop OpenNIC (!2073) · Merge Requests · PRISM Break / PRISM Break". GitLab. 19 December 2018. Archived from the original on 2021-01-28. Retrieved 2021-01-23.
  15. ^ "Should OpenNIC drop support for NameCoin [OpenNIC Wiki]". Archived from the original on 2021-10-29. Retrieved 2021-01-23.
  16. ^ "OpenNIC does the right thing: listens to security concerns and shuts down its centralized Namecoin inproxy". Archived from the original on 2022-03-24. Retrieved 2021-03-02.
  17. ^ "Namecoin : l'intégrité, mais à quel prix?". ZDNet France (in French). 2019-08-01. Archived from the original on 2021-11-23. Retrieved 2021-11-27.
  18. ^ "What is Namecoin's relationship to OpenNIC?". Archived from the original on 2022-07-26. Retrieved 2021-03-02.

Further reading

  • Judmayer, Aljosha; Stifter, Nicholas; Krombholz, Katharina; Weippl, Edgar (2022) [2017]. Blocks and Chains: Introduction to Bitcoin, Cryptocurrencies, and Their Consensus Mechanisms. Cham: Springer Nature. pp. 47–49. doi:10.1007/978-3-031-02352-1. ISBN 978-3-031-01224-2. ISSN 1945-9742. S2CID 249533342. Retrieved 2022-06-25 – via Google Books.
  • Haferkorn, Martin; Quintana Diaz, Josué Manual (2015). "Seasonality and Interconnectivity Within Cryptocurrencies – An Analysis on the Basis of Bitcoin, Litecoin and Namecoin". In Lugmayr, Artur (ed.). Enterprise Applications and Services in the Finance Industry: 7th International Workshop, FinanceCom 2014, Sydney, Australia, December 2014, Revised Papers. Cham: Springer Nature. p. 110. doi:10.1007/978-3-319-28151-3. ISBN 978-3-319-28150-6. ISSN 1865-1348. S2CID 37289572. Retrieved 2022-06-25 – via Google Books.
  • Karame, Ghassan; Androulaki, Elli (2016). Bitcoin and Blockchain Security. Boston: Artech House. p. 165. ISBN 978-1-63081-013-9. Retrieved 2022-06-25 – via Google Books.
  • Bheemaiah, Kariappa (2017). The Blockchain Alternative: Rethinking Macroeconomic Policy and Economic Theory. New York: Apress. p. 77. ISBN 978-1-4842-2673-5. Retrieved 2022-06-25 – via Google Books.
  • Franco, Pedro (2015). Understanding Bitcoin: Cryptography, Engineering and Economics. West Sussex: Wiley. p. 174. ISBN 978-1-119-01914-5. Retrieved 2022-06-25 – via Google Books.
  • Kirillova, Elena Anatolyevna; Pavlyuk, Albert Valentinovich; Mikhaylova, Irina Aleksandrovna; Zulfugarzade, Teymur E.; Zenin, Sergey S. (2018). "Bitcoin, Lifecoin, Namecoin: The Legal Nature of Virtual Currency". Journal of Advanced Research in Law and Economics. 9 (31): 119. doi:10.14505//jarle.v9.1(31).16. S2CID 169842085. Archived from the original on 2022-06-25. Retrieved 2022-06-25 – via Central and Eastern European Online Library.
  • Chang, Tao-Hung; Svetinovic, Davor (2016). "Data Analysis of Digital Currency Networks: Namecoin Case Study". 2016 21st International Conference on Engineering of Complex Computer Systems (ICECCS). Institute of Electrical and Electronics Engineers. pp. 122–125. doi:10.1109/ICECCS.2016.023. ISBN 978-1-5090-5526-5. S2CID 9397221. Archived from the original on 2022-06-25. Retrieved 2022-06-25.