Independent IOTA developer Roman Semko tweeted on September 10, 2018, that a bare bones prototype for the Nelson 2.0 Reference Implementation tested successfully in a large scale simulation. The experimental node software was able to function and reach a 100% confirmation rate on transactions even in a situation where 90% of all nodes in the network have gone rogue.

As the purpose of the Coordinator is to protect the fledgling Tangle from attacks until traffic grows strong enough to resist attacks, Semko’s results are a promising step toward a Tangle where the Coordinato is no longer needed.

Good Riddance?

The Coordintor is possibly the most controversial aspect of IOTA, the massively ambitious crypto giant paving the way to the Internet of Things. Or at least, it is certainly the aspect that gets the most criticism.

At its core the tangle is as decentralized as any blockchain, but the unique architecture of IOTA means that the tangle can be vulnerable to attackers spamming dishonest transactions. This vulnerability, as with the risk of 51% attacks on any regular blockchain, grows harder to exploit the more computing power is spent by miners securing the network.

With IOTA, there are no miners in the ordinary sense, only a very small amount of proof of work required to make a transaction. Thus, in the case of IOTA, an attack on the network would take the form of spamming a high number of transactions, and resistance to attacks is determined by the volume of honest transactions.

Centralized Coordinator

While volume on the tangle is low enough that attacks could realistically be a threat, the IOTA Foundation runs a centralized Coordinator. The Coordinator issues ‘milestone’ transactions once per minute, checkpointing valid transactions and making sure honest nodes do not get lost in any potential seas of malicious garbage transactions. While the Coordinator does protect against attacks, many detractors feel that relying on a closed source, centralized defense mechanism effectively centralizes the whole IOTA project.

It is worth pointing out that the protocol works perfectly fine without the Coordinator – it just protects against attacks. Nevertheless, it has been a source of much frustration to some, and a large roadblock to be overcome to others.

And yesterday we may have seen a significant step in the right direction. Nelson is the name of one reference implementation that is being worked on independently of the IOTA Foundation, and with the in-development 2.0 version it appears that resistance to attacks on the tangle will increase significantly.

Tweet posted by Roman Semo:

Preliminary #DeviotaNikita tests with a #DeviotaNelson 2.0 barebone prototype: Running 100% confirmation rate in a +90% hostile environment (10 vs 90 nodes) whereas the attacker's hash power does not matter. ?? — Roman Semko [Deviota] (@RomanSemko) September 10, 2018

In a test with 10% honest nodes running the experimental Nelson implementation and 90% dishonest nodes, honest transactions reached a 100% confirmation rate without any of the malicious transactions being accepted by the honest nodes. While the honest nodes had the advantage of not having to deal with honest nodes running older software versions, they also did not have anything like a central coordinator to boost honest transactions.

Instead the honest nodes were left to find each other in a sea of spammed garbage. And with automatic peer discovery and a lot of rejecting bad transactions from the cheater nodes, they did.

The test was conducted using an experimental ‘bare bones’ prototype, and we should not expect Nelson 2.0 to be rolled out to the wider community any time soon, but the results are impressive, and if everything goes well, the Coordinator may eventually be rendered unnecessary not by the hands of the IOTA Foundation, but by the work of independent members of the community.