Staking in Cardano (1/3) The general perspective

Advice for Stakeholders – Delegators and Stake Pool Operators.

This is a translation of the original IOG blog post

As a project, decentralization remains arguably our most important and fundamental goal for Cardano. Protocols and parameters provide the foundations for any blockchain. Last week, we outlined some of the planned changes around Cardano parameters and how these will impact the staking ecosystem and thus accelerate our decentralization mission.

Yet the community itself – how it sees itself, how it behaves, and how it sets common standards – is a key factor in the pace of this success. Cardano has been very carefully engineered to provide “by design” all the necessary properties for a blockchain system to operate successfully. However, Cardano is also a social construct, and as such, observance, interpretation, and social norms play a crucial role in shaping its resilience and longevity.

So in anticipation of the k-parameter adjustment on December 6th, I would like to give a broader perspective on staking, highlighting some of the innovative features of the rewards sharing scheme used in Cardano.

Principles & practical intent

As well as outlining some of the key principles, this piece has a clear practical intent; to provide guidance and some recommendations to stakeholders so that they engage meaningfully with the mechanism, and support the project’s longer-term strategic goals through their actions.

Consensus based on a resource that is dispersed somehow across a population of users – as opposed to identity-based participation – has been the hallmark of the blockchain space since the launch of the Bitcoin blockchain. In this domain, proof-of-stake systems are distinguished in the sense that they use a virtual resource, stake, which is recorded in the blockchain itself.

Pooling resources for participation is something that is inevitable; some level of pooling is typically beneficial in the economic sense and hence resource holders will find a way to make it happen. Given this inevitability, the question arises: how does a system prevent a dictatorship or an oligarchy from emerging?

The objectives of the reward sharing scheme

Contrary to other blockchain systems, Cardano uses a reward sharing scheme that (1) facilitates staking with minimum friction as well as (2) it incentivizes pooling resources in a way that system-wide decentralization emerges naturally from the rational engagement of the resource holders.

The mechanism has the following two broad objectives:

  1. Engage all stakeholders – This is important since the more stakeholders are engaged in the system, the more secure the distributed ledger will be. This also means that the system should have no barriers for participation, nor should impose friction by requiring off-chain coordination between stakeholders to engage with the mechanism.
  2. Keep the leverage of individual stakeholders low -. Pooling resources leads to increased leverage for some stakeholders. Pool operators exert an influence in the system proportional to the resources controlled by their pool, not to their own resources. Without pooling, all resource holders have leverage of exactly 1; contrast this e.g., to a pool operator, owning, say 100K ada, who controls a pool of total delegated stake of 200M ada; that operator has leverage of 2,000. The higher the leverage of the system, the worse its security (to see this, consider that with leverage above 50, launching a 51% attack requires a mere 1% of the total resources!).

It should also be stressed that a disproportionately large pool size is not the only reason for increased leverage; stakeholders creating multiple pools, either openly or covertly (what is known as a Sybil attack) can also lead to increased leverage. The lower the leverage of a blockchain system, the higher its degree of decentralization.

Putting this into practice

So how does the reward sharing scheme used in Cardano meet the above objectives? Staking via our scheme facilitates two different paths: pledging and delegating. Pledging applies to stake pool operators; pledged stake is committed to a stake pool and is supposed to stay put for as long as the pool is operating. Think of pledge as a ‘commitment’ to the network – ‘locking up’ a certain amount of stake in order to help safeguard and secure the protocol. Delegating on the other hand, is for those who do not wish to be involved as operators. Instead, they are invited to assess the offerings the stake pool operators provide, and delegate their stake to one or more pools that, in their opinion, best serve their interests and the interest of the community at large. Given that delegation does not require locking up funds, there is no reason to abstain from staking in Cardano; all stakeholders can and are encouraged to engage in staking.

Central to the mechanism’s behavior are two parameters: k and a0. The k-parameter caps the rewards of pools to 1/k of the total available. The a0 parameter creates a benefit for pledging more stake into a single pool; adding X amount of pledge to a pool increases its rewards additively by up to a0*X. This is not to the detriment of other pools; any rewards left unclaimed due to insufficient pledging will be returned to the Cardano’s reserves and allocated in the future.

Beyond deciding on an amount to pledge, creating a stake pool requires that operators declare their profit margin and operational costs. When the pool rewards are allocated at the end of each epoch, the operational costs are withheld first, ensuring that stake pools remain viable. Subsequently, operator profit is calculated, and all pool delegators are rewarded in ada proportional to their stake afterwards.

Paired with the assessment of stake pools performed by the delegates, this mechanism provides the right set of constraints for the system to converge to a configuration of k equal size pools with the maximum amount of pledge possible. The equilibrium point has the property that delegator rewards are equalized (so it doesn’t matter what pool they delegate to!), while stake pool operators are rewarded appropriately for their performance, their cost efficiency, and their general contributions to the ecosystem.

For the above to happen, it is necessary to engage with the mechanism in a meaningful and rational manner. To assist stakeholders in understanding the mechanism, here are some points of advice.

Continue with a

If you are a Cardano stakeholder, we hope that you find the above advice informative and helpful in your efforts to engage in staking. As in many other respects, Cardano brings a novel and heavily researched mechanism to its blockchain design. The rewards scheme is mathematically proven to offer an equilibrium that meets the set of objectives set out in the beginning of this document. Ultimately though, the math is not enough; it is only the people that can make it happen.

Cardano’s future is in the hands of the community.

The opinions expressed in the blogpost are for educational purposes only and are not intended to provide any form of financial advice.