Full decentralization lies at the heart of Cardano’s mission. While it is not the only goal that we're focused on, in many ways, it is a goal that will enable and accelerate almost every other. It is integral to where we want to go as a project.

It is also where the philosophical and technical grounding of the entire Cardano project meets its community, in very real and tangible ways. This is why we have done a lot of thinking on how to achieve decentralization effectively, safely, and with the health of the ecosystem front of mind.

Defining decentralization

Let’s start by explaining what we mean by decentralization. This is a word that is fraught with challenge, with several competing meanings prevalent in the blockchain community.

For us, decentralization is both a destination and a journey. Shelley represents the first steps toward a fully decentralized state; from the static, federated approach of Byron to a fully democratic environment where the community not only runs the network, but is empowered and encouraged to take decisions through an on-chain framework of governance and voting.

True decentralization lies at the confluence of three essential components, working together in unison.

• Networking - where geographically distributed agents are linked together to provide a secure and robust blockchain platform.
• Block production - where the work of building and maintaining the blockchain is distributed across the network to a collection of cooperating stake pools.
• Governance - where decisions about the blockchain protocol and the evolution of Cardano are taken collectively by the community of Cardano stakeholders.

Only when all these factors exist within a single environment can true decentralization be said to have been achieved successfully.

Key parameters that affect decentralization

Let's talk about d, maybe.

The d-parameter performs a pivotal role in controlling the decentralization of block production. Decentralization is a spectrum, of course, rather than an absolute. In simple terms, d controls ‘how’ decentralized the network is. For example, at one extreme, d=1 means that block production is fully centralized. In this state, IOG’s core nodes produce all the blocks. This was how Byron operated,

Conversely, once d=0, and decentralized governance is in place and on chain, ‘full’ decentralization will have been achieved. At this point, stake pool operators produce all the blocks (block production is 100% decentralized), the community makes all the decisions on future direction and development (governance is decentralized), and a healthy ecosystem of geographically distributed stake pools are connected into a coherent and effective network (the network is decentralized). We will have reached our decentralization goal.

The journey that d will take from 1 to 0 is a nuanced one that requires a careful balance between the action of the protocol and the reaction of the network and its community. Rather than declining instantly, d will go through a period of ‘constant decay’ where it is gradually decremented until it reaches 0. At this point Cardano will be fully decentralized. This gradual process will allow us to collect performance data and to monitor the state of the network as it progresses towards this all-important point. A parameter-driven approach will help provide the community with transparency and a level of predictability. Meanwhile, we’ll be monitoring the results carefully; there will always be socio-economic and market factors to consider once ‘in the wild’.

How will the d parameter change over time

The evolution from 1 to 0 is relatively simple:

When d=1, all blocks are produced by IOG core nodes, running in Ouroboros Byzantine Fault Tolerance (OBFT) mode. No blocks are produced by stake pool operators (running in Ouroboros Praos mode). All rewards go to treasury.

When d=0, the reverse becomes true: every block will be produced by stake pools (running in Praos mode), and none by the IOG core nodes. All rewards go to stake pools, once the fixed treasury rate is taken.

In between these extremes, a fraction of the blocks will be produced by the core nodes, and a fraction by the stake pools. The precise amounts are determined by d. So when d reaches 0.7, for example, 70% of the blocks will be produced by the core nodes and 30% will be produced by stake pools. When d subsequently reaches 0.2, 20% of the blocks will be produced by the core nodes, and 80% by the stake pools.

It is important to note that regardless of the percentage of blocks that are produced by the stake pools, however, once d < 1, all the rewards will go to stake pools in line with the stake that they hold (after the fixed treasury percentage is taken), and none to the core nodes. This means that IOG has absolutely no incentive to keep the d parameter high. In fact, when d reaches zero, IOG will be able to save the costs of running the core nodes, which are not insubstantial.

Like many other ada holders, IO Global is currently running a number of stake pools on the mainnet. As the creator of the Cardano platform, IO Global naturally has a significant stake in its success from fiscal, fiduciary, and security aspects, and this success will be built on a large number of effective and decentralized pools. As a commercial entity, IO needs to generate revenue from its stake, while recognizing the part it needs to play within an ecosystem of stake pools, helping to grow and maintain the health of the network as we move towards full decentralization. In the medium term, we will follow a private/public/community delegation approach, similar to that we adopted on the ITN, spreading our stake across both IOG and community pools. In the short term, however, we are running IOG pools on the mainnet, establishing a number of our own pools that can take some of the load from our core nodes. Using our stake and technical expertise to secure and stabilise the network is an important element at first, but one that will become less important as the d parameter decreases. The road to decentralization will offer many opportunities for pools of all sizes to establish themselves and thrive along the way.

The key milestones of the d journey

d<1.0 (Move away from centralization)

The first milestone happened on August 13 at the boundary of epoch 210 and 211 when the d parameter first dropped below 1.0. At this point, IOG's core nodes started to share the block production of blocks with community stake pools. This marks the beginning of the road to full decentralization.

d=0.8 (Stake pools produce 20% of blocks)

At 0.8, more pools (double the number compared to d=0.9) will get the opportunity to create blocks and establish themselves. At this level, pools won’t suffer in the rankings as long as they create one of the allocated blocks and get rewards. This way, we believe we can start growing the block-minting proportion of the network, at low network risk.

d<0.8 (Stake pool performance taken into account)

The next major milestone will happen when d drops below 0.8. Below that level, each pool's performance will be taken into account when determining the rewards that it receives. Above that level, however, the pool’s performance is ignored. The reason for this is to avoid unfairness to pools when they are only expected to produce a few blocks.

d<0.5 (Stake Pools Produce the Majority of Blocks)

When d drops below 0.5, stake pools will produce the majority of blocks. The network will have reached a tipping point, where decentralization is inevitable.

Before taking this dramatic step, we will ensure that two critical features are in place: peer-to-peer (P2P) pool discovery and protocol changes to enable community voting. These will enable us to make the final push to full and true decentralization The recently announced Project Catalyst program was the first step in this, concurrent journey to full on-chain governance.

d=0 (Achieve Full Decentralization)

As soon as the parameter reaches 0, the IOG core nodes will be permanently switched off.

IOG will continue to run its own stake pools that will produce blocks in line with the stake they attract, just like any other pools. But these will no longer have any special role in maintaining the Cardano network. It will also, of course, delegate a substantial amount of its stake to community pools. Simultaneously, the voting mechanism will be enabled, and it will no longer be possible to increase d and ‘re-centralize’ Cardano.

At this point in time, we will have irrevocably entered a fully decentralized Cardano network. Network + block production + on-chain governance = decentralization.

Rate of constant decay

The progressive decrement of d is known as constant decay. The gradual decrease will give us the chance to monitor the effects of each decrement on the network and to make adjustments where necessary. As the parameter decreases, more stake pools will also be able to make blocks, since the number of blocks that are made by the pools will increase, and less stake will then be required for each block that is made.

The key factors driving this decrease will be:

• The resilience and reliability of the network as a whole.
• The number of effective block-producing pools.
• The amount of the total stake that has been delegated.

Here’s our current thinking on what implementation might look like:

We will then likely pause before dropping the parameter below 0.5 to ensure that the two key conditions described above are met:

• The implementation of the new Peer-to-Peer pool discovery mechanism has been released and is successfully in use;
• We have successfully transitioned the first hard fork in the Shelley era, which will introduce the basis for community voting on protocol parameters, and other important protocol changes

We will resume the countdown to d=0 at a similar rate, pausing again if necessary before finally transitioning to d=0 in March 2021.

Other factors that affect decentralization: Saturation threshold

A second parameter – k – is used to drive growth in the number of pools by encouraging delegators to spread their stake. By setting a cap on the amount of stake that earns rewards (the saturation threshold), new delegators are directed towards pools that have less stake. In ideal conditions, the network will stabilise towards the specific number of pools that have been targeted. In practice, we saw from the ITN that many more pools than this number were supported by the setting that we chose.

The k parameter was set to 150 at the Shelley hard fork. This setting was chosen to balance the need to support a significant number of stake pools from the start of the Shelley era against the possibility that only a small number of effective pools would be set up by the community. In due course, it will be increased to reflect the substantial number of pools that have emerged in the Cardano ecosystem since the hard fork. This will spread stake, and so block production, among more pools. The overall goal in choosing the setting of the parameter will be to maximise the number of sustainable pools that the network can support, so creating a balanced ecosystem. In order to achieve this, a careful balance is required between opening up the opportunity to run a block-creating pool to as many pools as want to run the system, against the raw economics of running a pool (from bare metal servers, to cloud services, to people’s time), taking into account the rewards that can be earned from the actively delegated stake. Changing this parameter will therefore be done with a degree of caution and balance so that we ensure the long term success of a fully decentralized Cardano network. We’re now looking carefully at early pool data and doing some further modelling before making the next move.

d and pool rewards

Two questions remain: What is the effect of d on the rewards that a pool can earn, and can this parameter ever be increased?

Regarding rewards, as long as a pool produces at least one block, the value of the parameter has absolutely no effect on the rewards that a pool will earn – only on the number of blocks that are distributed to the pools. So if a pool has exactly 1% of the stake, it will earn precisely 1% of the total rewards, provided that it maintains its expected performance.

Finally, while d could in theory be increased, there would need to be a truly compelling reason to do so (a major protocol issue, or fundamental network security, for example.) We would never envision actually doing this in practice. Why? Simply because we want to smoothly and gradually reduce the parameter to 0 in order to achieve our objective of true decentralization. We’ll be making this journey carefully but with determination step by step. If each step is taken thoughtfully and with confidence, you should not need to retrace them? As d becomes 0, the centralized IO servers will be finally switched off, and Cardano will become a model of decentralized blockchain that others aspire to be.

Conclusion

The decline of centralized entities coincides with Cardano's rise towards full and true decentralization. In the near future, the Cardano blockchain will be solely supported and operated by a strong community of stake pools whose best interest is the health and further development of the network.

This journey, which began with Shelley and the implementation of the d parameter, will take Cardano through a path of evolutionary stages in which the network will become progressively more and more decentralized, as d decays. The journey will only end when the blockchain enters a state of irrevocable decentralization, a moment in time that will see networking, block production, and governance operating in harmony within a single environment.

Taking a decentralized approach to governance and decision-making is proving to be more efficient in many spheres than the centralized, authority-based model that became the norm in so many areas in the last century. At IOHK, we believe that blockchain technology offers a way to encourage participation in collective action. And we are building just such a system, so Cardano can grow in a fair and decentralized way, with an open governance system that encourages global participation by granting ada holders the power to make decisions.

Decentralization is core to global governance

As we’ve been working on this, the pandemic crisis has exposed weaknesses in our globalized economy and made it clear that everyone needs to reconsider the ways we collaborate in the face of challenging international situations. Over recent decades, the world has become ever more connected through digital infrastructure and social platforms. Therefore, robust tools and new behavior patterns are now necessary to improve the way we collaborate.

In the past, large collective challenges had to be solved in a centralized manner by high-level actors governing from the ‘top’ down. In that governance model, power, authority, and control were decided and exercised at management level. This could be a chief executive, a president, or even a dictator determining the ‘best’ course of action. In this centralized system, once a decision is made, it becomes the law of the land, and new behaviors are enforced. However, the top-down model is inefficient for solving global-scale challenges. Dr Mihaela Ulieru, an adviser on digital ecosystems organization and transformation, spoke at the recent Cardano Virtual Summit about her vision of ‘bottom-up’ organic governance. There, she pointed out that hierarchical structures are rigid and less productive. Furthermore, they cannot deal efficiently with emerging complexity.

A centralized governance model depends on the limited knowledge, expertise, and understanding of a single individual or a body of actors. Decisions must then proliferate through the system to deal with emerging problems. This generates an inflexible response that lacks on-the-ground information from the people affected by a particular event. Therefore, the more complex and widespread a problem is, the less prepared a top-down organization can deal with it in a way that works for most people. So the question arises, how do we create a system that responds to emerging problems, aids decision-making, and remains all-inclusive?

Dr Ulieru reminds us that the bottom-up approach has been used in peer-to-peer networks to great effect allowing network participants to collaborate in a way that is reflective of the desires and needs of the community. SoScial.Network, launched by Jon Cole after Hurricane Harvey hit the southern US in 2017, is one example. This network enabled people and communities to gather and offer help to each other by providing aid to disaster victims. Another social network, ChefsForAmerica, delivers food to hospitals, the disadvantaged, and those in need. AgeWell created a peer-to-peer care delivery model that improves the well-being and health of elderly people, keeping them in their homes, while reducing their healthcare costs. Such activity, organized by individuals in a decentralized manner, can solve challenges faster and collaboratively.

Cardano decentralization

For effective collaboration on decision-making, Cardano offers a decentralized network built on a blockchain for a higher level of security and transparency. It takes the networking peer-to-peer concept further and builds it into a global infrastructure. For Cardano to establish a solid governance model, it is important to ensure that everyone can participate in a transparent, accountable, and responsive way. As decentralization empowers individuals and communities to take action and collaborate, anyone can suggest a change, or an activity to be initiated, whether this is for social good or for technological progress.

The question is, how to decide which change is crucial and what exactly will benefit everyone? Crucially, who will pay for its realization? To solve these issues, Cardano is establishing a global voting and treasury systems for funding the blockchain long-term development. Hence, decision-making and funding are two crucial components of governance. At IOHK, we worked to solve these issues and to provide the tools to empower decentralized governance and improve all our systems.

Voltaire and ada holders

For Cardano, a decentralized governance model should grant all ada holders the ability to decide what changes should be made for the ecosystem to grow and mature. When building an ecosystem for the next century rather than the next decade, the self-sustainability of the network becomes vital. Since individuals in the Cardano ecosystem are most affected by the decisions made about the protocol, it is important for them to understand how those decisions are made and how they are paid for, as well as how to participate in that process.

Voltaire is the era in Cardano development that deals with decentralized governance and decision-making. Voltaire focuses on the Cardano community’s ability to decide on software updates, technical improvements, and project funding. To provide the final components that turn Cardano into a self-sustainable blockchain, we need to introduce:

• A treasury system: a continuous source of funding to develop the Cardano blockchain.
• Decentralized software updates: the process enabling decentralized, open participation for fair voting on decisions about system advancements.

In line with that, IOHK’s engineers are implementing tools and social experiments to enable Cardano’s governance framework. Hence, we are working on:

• Cardano improvement proposals (CIPs): a social communication system for describing formal, technically-oriented standards, codes, and processes that provide guidelines for the Cardano community in a transparent and open-source way.
• Project Catalyst: an experimental treasury system combining proposal and voting procedures.

Project Catalyst focuses on making the treasury system a reality by establishing a democratic culture for the Cardano community. This goal will be achieved by a combination of research, social experiments, and community consent. Catalyst enables the community to make proposals, vote on them, and fund them according to their feasibility, auditability and impact.

It is important to note that everyone has an equal right to propose changes and system enhancements, and that everyone is encouraged to collaborate on innovative and powerful proposals.

To ensure that everyone gets a say, we are establishing a ballot submission system where people can propose improvements. This may be a proposal to sustain a system, to market it, or perhaps a suggestion to improve an existing protocol. In addition, IOHK wants to enable our community to create products or applications aimed at solving challenges within the market.

To suggest such contributions, people can submit ballots to the community. After the ballots are submitted, voting will decide which proposals can move forward.

Voting is the exercise of influence to decide which proposals get accepted or rejected. Only by encouraging everyone to participate can we ensure that preferences are determined in a democratic way. The value of Catalyst, though, lies not only in the technology improvement, but also in enabling the community to learn how to collaborate, make good decisions, and essentially, generate great proposals. So, decisions are taken through a robust set of voting protocols that we are developing. These will be evaluated by the community with the help of members who can put themselves forward as ‘experts’ to help explain proposals.

Although any ada holder can submit a proposal, the voting power of an individual is proportional to the amount of ada that is ‘locked’ into the system when people register. By voting, participants will influence decisions on which proposals to fund for network development and maintenance. This could also lead to the creation of educational materials, marketing strategies, technical improvements processes, and many other ideas.

Another feature of Catalyst is privacy. As in any political elections, this is key for preventing voter coercion and helping defend against corruption. So, Cardano is looking to implement a zero-knowledge proof for each vote. This cryptographic technique grants privacy by allowing the vote to be verified without it being publicly revealed.

The treasury funds proposals

A crucial aspect of a self-sustainable network is understanding who will fund decisions and proposals. To meet these needs, Cardano is introducing a self-sustainable treasury system to fund blockchain enhancements and maintenance. The main sources of capital will be refilled every epoch from a portion of stake pool rewards, and later from minted new coins, the percentage from fees, and additional donations or charity.

Project Catalyst will maintain this constant source of funding. A steady income stream will support initiatives and improvements proposed by ada holders, while at the same time rewarding and incentivizing people who dedicate their time and effort to making productive decisions. This will enable the establishment of a decentralized system that promotes participation, collaborative decisions, and incentivization. Besides the funding purposes, Catalyst ensures that funds are used well, facilitating the flow of information so the community is able to assess proposals while addressing the most important needs of the ecosystem.

IOHK is building a decentralized financial system that can address the world's needs. Voltaire is the first step in this direction. Using a collection of concepts, tools, and experiments, we are creating a fully decentralized ecosystem that will democratize our blockchain, and open it to the world.

Want to help shape the future of Cardano? Project Catalyst is looking for 25 community members to join a focus group on the direction of the program, pitch their ideas, and test the platform and voting. If you have an idea that might be suitable for funding, or would like to join a panel assessing community ideas, apply today! Please ensure you have a Telegram and an email account to apply by midnight UTC on Friday, August 7.