CodeXNO[a] (formerly NANO, XRB)
Previous namesRaiBlocks[1]
Precision10−30 (raw)
Original author(s)Colin LeMahieu
White paper"Nano – Digital money for the modern world"
Initial release4 October 2015 (8 years ago) (2015-10-04)
Latest releaseV25.1 "Daric" / 2 June 2023 (12 months ago) (2023-06-02)
Development statusActive
Written inC++
Developer(s)Nano Foundation
Timestamping scheme"Open Representative Voting", a form of proof-of-stake
Hash functionBlake2
Issuance scheduleCaptcha faucet (ended 20 October 2017; 6 years ago (2017-10-20))
Supply limit133,248,297
  1. ^ Compatible with ISO 4217, though is not approved

Nano (Abbreviation: XNO) is a cryptocurrency characterized by a directed acyclic graph data structure and distributed ledger, making it possible for Nano to work without intermediaries. To agree on what transactions to commit (i.e., achieving consensus), it uses a voting system with weight based on the amount of currency an account holds.[2][3]

Nano was launched in October 2015 by Colin LeMahieu to address the Bitcoin scalability problem and was created to reduce confirmation times and fees.[4] The currency implements no-fee transactions and achieves confirmation in under one second.[5]


Colin LeMahieu started the development of Nano in 2014 under the name "RaiBlocks".[1][6] A year later, RaiBlocks was distributed for free through a captcha-secured faucet.[7] In 2017, after 126,248,289 RaiBlocks were distributed, the faucet shut down. This fixed the total supply to 133,248,297 RaiBlocks, after addition of a 7,000,000 RaiBlocks developer fund.[8] RaiBlocks was rebranded as Nano in 2023.[9]

BitGrail hack

On February 9, 2018, an Italian cryptocurrency exchange BitGrail announced its hack and eventual shutdown.[10] Users were prevented from accessing assets stored on the platform, which was collectively worth 17 million Nano.[11] The victims then launched a class-action lawsuit against BitGrail owner Francesco Firano for recoupment, inside the Florence Courthouse. The exchange was ruled to be guilty in January 2019, as it was found to fail at implementing safeguards and reporting losses.[12] The Italian police branch Network Operations Command (Italy) alleged the Bitgrail founder had conducted fraud.[13] Nano prices had been around $10 prior to the hack and after the hack fell to $0.10.[14]


Nano uses a block-lattice data structure, where every account has its own blockchain for storing transactions.[15][16] It is the first cryptocurrency to use a directed acyclic graph data structure,[17] by having a "block" consisting of only one transaction and the account's current balance.[18][15]

Nano's consensus algorithm is similar to proof of stake.[19] In this system, the voting weight is distributed to accounts based on the amount of Nano they hold; accounts then freely delegate this weight to a peer (node) of their choice.[20]

If two contradictory transactions are broadcast to the network, indicating a double-spend attempt, nodes will vote for both transactions and broadcast their vote to the other nodes. The first transaction to reach 67% of the total voting weight is confirmed, while the other is considered invalid.[21][non-primary source needed]


  1. ^ a b Baldwin, Rosecrans (2019-11-26). "Cryptocurrency Will Not Die Archived 2020-12-03 at the Wayback Machine". GQ. Retrieved 2020-12-22.
  2. ^ Hrga, Alen; Capuder, Tomislav; Podnar Žarko, Ivana (2020). "Demystifying Distributed Ledger Technologies: Limits, Challenges, and Potentials in the Energy Sector". IEEE Access. 8: 2169–3536. Bibcode:2020IEEEA...8l6149H. doi:10.1109/ACCESS.2020.3007935. S2CID 220667938.
  3. ^ Bencic, Federico Matteo; Podnar Zarko, Ivana (2018). "Distributed Ledger Technology: Blockchain Compared to Directed Acyclic Graph". 2018 IEEE 38th International Conference on Distributed Computing Systems (ICDCS). pp. 1569–1570. arXiv:1804.10013. doi:10.1109/ICDCS.2018.00171. ISBN 978-1-5386-6871-9. S2CID 13741873.
  4. ^ Easley, David; O'Hara, Maureen; Basu, Soumya (2019). "From mining to markets: The evolution of bitcoin transaction fees". Journal of Financial Economics. 134: 91–109. doi:10.1016/j.jfineco.2019.03.004. S2CID 158896456.
  5. ^ Morais, Rui; Crocker, Paul; Melo De Sousa, Simao (2020). "A Tool for Implementing Privacy in Nano". 2020 IEEE International Conference on Decentralized Applications and Infrastructures (DAPPS). pp. 159–163. doi:10.1109/DAPPS49028.2020.00021. hdl:10400.6/7645. ISBN 978-1-7281-6978-1. S2CID 209471367.
  6. ^ Github (2014-05-01). "[1] Archived 2020-10-16 at the Wayback Machine". Github. Retrieved 2022-21-09.
  7. ^ Bottone, Michele; Raimondi, Franco; Primiero, Giuseppe (2018-07-23). "Multi-agent Based Simulations of Block-Free Distributed Ledgers". 2018 32nd International Conference on Advanced Information Networking and Applications Workshops (WAINA). Krakow, Poland. pp. 585–590. doi:10.1109/WAINA.2018.00149. ISBN 978-1-5386-5395-1. S2CID 50774787. Archived from the original on 2022-04-03. Retrieved 2022-02-11.((cite book)): CS1 maint: location missing publisher (link)
  8. ^ Wall Street Journal (2018-03-03). "Crypto Investing Comes With a Big Risk: The Exchanges Archived 2018-03-07 at the Wayback Machine". Wall Street Journal. Retrieved 2022-09-23.
  9. ^ "Nano Price: Raiblocks Cryptocurrency Rebrands as XRB Price Soars". Inverse. 2018-01-31. Retrieved 2024-05-25.
  10. ^ Morris, David (11 February 2018). "BitGrail Cryptocurrency Exchange Claims $195 Million Lost to Hackers". Fortune. Retrieved 22 October 2022.
  11. ^ Vigna, Paul (2018-02-10). "Cryptocurrency Worth $170 Million Missing From Italian Exchange Archived 2019-05-25 at the Wayback Machine". The Wall Street Journal. Retrieved 2019-12-18.
  12. ^ Canellis, David (2019-01-28). "Italian court forces BitGrail CEO to repay $170M in 'lost' cryptocurrency Archived 2020-11-08 at the Wayback Machine". The Next Web. Retrieved 2019-12-18.
  13. ^ "Italian police accuse cryptocurrency exchange boss of huge fraud". Reuters. 21 December 2020. Retrieved 22 October 2022.
  14. ^ Hatmaker, Taylor (12 February 2018). "Italian cryptocurrency exchange gets hacked for $170 million in Nano". Techcrunch. Retrieved 22 October 2022.
  15. ^ a b Shahaab, A.; Lidgey, B.; Hewage, C.; Khan, I. (2019). "Applicability and Appropriateness of Distributed Ledgers Consensus Protocols in Public and Private Sectors: A Systematic Review". IEEE Access. 7: 43622–43636. Bibcode:2019IEEEA...743622S. doi:10.1109/ACCESS.2019.2904181. S2CID 108390582.
  16. ^ Xiao, Y.; Lou, W.; Thomas Hou, Y. (2020). "A Survey of Distributed Consensus Protocols for Blockchain Networks". IEEE Communications Surveys & Tutorials. 22 (2): 1432–1465. arXiv:1904.04098. doi:10.1109/COMST.2020.2969706.
  17. ^ Masood, Faraz; Faridi, Arman Rasool (2018). "Consensus Algorithms in Distributed Ledger Technology for Open Environment". 2018 4th International Conference on Computing Communication and Automation (ICCCA). pp. 1–6. doi:10.1109/CCAA.2018.8777695. ISBN 978-1-5386-6947-1. S2CID 199057702.
  18. ^ Werner, Robert et al. (2020). "Anonymization of Transactions in Distributed Ledger Technologies". Twelfth International Conference on Adaptive and Self-Adaptive Systems and Applications. p. 69. ISBN 978-1-61208-781-8.
  19. ^ Mercan, Suat; Kurt, Ahmet; Erdin, Enes; Akkaya, Kemal (2021). "Cryptocurrency Solutions to Enable Micro-payments in Consumer IoT". IEEE Consumer Electronics Magazine. Vol. 11, no. 2. pp. 97–103. doi:10.1109/MCE.2021.3060720.
  20. ^ Khalifa, Amr; Bahaa-Eldin, Ayman; Sobh, Mohamed (2019). Blockchain and its Alternative Distributed Ledgers - A Survey. 2019 14th International Conference on Computer Engineering and Systems (ICCES). doi:10.1109/ICCES48960.2019.9068183.
  21. ^ Nano. "Protocol Design - ORV Consensus". Archived from the original on 20 February 2021. Retrieved 27 February 2021.