A simple explanation of the IOTA Coordicide

4 min readFeb 25, 2019


In the last few days a lot has been said and speculated about Coordicide. Maybe not every person knows exactly what the Coordinator and the Coordicide is and what kind of implications arise. We want to provide education with this little essay.

Source: https://blog.iota.org/coordinator-part-1-the-path-to-coordicide-ee4148a8db08

In order to protect the Tangle in its early phase attacks, IOTA uses the review so called “Coordinator” (also: “Coo”). The Coo is a special node operated by the IOTA Foundation. He regularly publishes zero-value transactions that perform a checkpoint function on Tangle. These transactions, also called “milestones”, determine the direction in which Tangle is being spun. A transaction is only valid if it is confirmed by the coordinator directly or indirectly with a “milestone”.

The use of the coordinator often meets with criticism in the crypto scene, because in principle he gives the IOTA Foundation the last word on the status quo of the network. Although the Foundation can not retroactively invalidate transactions; however, it could de facto freeze deposits of participants in the network where the coordinator does not take their transactions into account when publishing new milestones. In addition, an attack on the coordinator could paralyze the whole Tangle. Last but not least, the use of the coordinator curtails the scalability of IOTA, which is actually one of the greatest strengths of the protocol.

The above criticism can be summed up in one word: centralization. The criticism does not fall on deaf ears at IOTA, on the contrary: The Coo was provided from the beginning as a temporary solution. On the question of the end of the coordinator, the IOTA Foundation writes in its blog:

“ The short answer is that the coordinator can and will be removed if our research team is convinced that we sufficiently understand the coordinator-free Tangle.“

That’s why the IOTA Foundation plans to launch a coordinator-free testnet. Within this testnet, various theroetic approaches will be tested, which should make IOTA a long-term decentralized IoT platform without any scaling problems.

IOTA has reportedly settled on a plan to end centralization within its network by eliminating its coordinator node. The IOTA team was responsive, and they began working on a solution in late November. This process has been thoroughly outlined on the IOTA blog.

Three possible approaches were considered. First, a node accountability and reputation system was proposed. Next, an improved tip selection algorithm with random walks was suggested. Finally, a constellation-like “star” system with trusted transaction pathways was considered.

Any of these solutions would eliminate the need for a coordinator node. It is likely that the IOTA Foundation will make an official announcement in the near future.

Many have hoped that the „IOTA Research Summit 2019“ will give them some more clarity about the specific design or schedule for eliminating the Coordinator.

Unfortunately, this meeting did not give any clarity to outsiders in this regard.The following has been published from the IOTA Foundation:

„The Coordicide and Attack Analysis teams mostly worked separately at the IOTA Research Summit 2019, but did come together at the end to present their progress to the whole department. These days afforded an opportunity for the creative process to take over, as clarity about questions, requirements, and next steps, guided the IOTA´s team’s work. The topics of coordicide and reusable addresses were a big focus, and much progress was made. The IOTA Team look forward to sharing more about everything in the future.“

On the Blockchain Istanbul 2019 IOTA´s Founder Sergey Popov talked about the coordicide. The youtube video can be viewed

“Coordicide” — IOTA’s step to decentralization

On the 5th of march the IOTA team announced that they started a test net without a coordinator. Znet, the new IOTA testnet will no longer run with a coordinator involved, allowing znet and IOTA to take huge steps towards a more enhanced decentralisation and of course, a more transparent network. This can be read in the article “ https://blog.iota.org/a-coo-less-testnet-879ad17ca1af” Alon Gal writes:

In order to simplify the first iteration of CLIRI, we have decided to completely remove ledger validation: all transactions are valid, as long as they meet the PoW requirement. This version will be run on a new testnet, which we call znet, which stands for “zero-value’. Our aim is to stabilize this code and establish its resilience, before implementing more complex validation logic.

We hope that we will soon receive specific information about the Coordicide and that it will implement the necessary path. This makes IOTA even stronger and it would also be a sign of strength for the critics.


Of course, we are also happy about donations for the realization of our Tangle Universe project. The following options are available:


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Thank you!

„public IOTA“ is not part of the IOTA Foundation or linked to any other way, it is an independent project to support IOTA and it´s applications.

We look forward to your message. Contact: info@publiciota.com




Interested in cryptocurrencies especially IOTA and member of the public IOTA project.