Polkadot has just announced that some parachains may not follow the auction model and get a slot depending on their public utility.
Polkadot is a scalable heterogeneous multi-chain blockchain designed to enable interoperability between different chains. Formed by a collaborative decentralized blockchain network called a relay chain, it interacts with chains running in parallel known as parachains. Polkadot chose this architecture from the outset to allow its blockchain to scale without compromise, entrusting the relay chain with the sole function of validating the state of the parachains.
By comparison, Ethereum uses its chain to validate transactions and at the same time run the Ethereum Virtual Machine (EVM). In any given block in the chain, Ethereum has one and only one “canonical” state and the EVM is what defines the rules for calculating a new valid state from block to block.
Polkadot’s parachains are limited to streamline the use of the relay chain’s computational power and to get a slot they must participate in an auction. The various parachain teams know what they are bidding for a slot, but they cannot know what other teams are bidding for the same slot. If they win, the project must lock the DOT pledged in the bid for the duration of the slot lease.
Polkadot: system-wide parachains and utility parachains
In a recent post on his official blog, Joe Petrowski published an introduction to what could be a major policy change on parachain slot allocation.
The researcher from Parity Technologies, the company behind Polkadot, identifies the ultimate goal as shifting any computational load away from the Relay Chain. Parachains that perform a public good service could then have a slot for their parachain without going through the auction process but through a vote on the network.
This always has to go through the network stakeholders, essentially those who are staking DOT on the network. Parachains for the public good would then be chosen through a public referendum, with the Polkadot Board and Technical Committee engaging in on-chain discussions and motions to accept or reject the direct registration of certain parachains.
Parachains for the public good can be divided into administrative functions (System Level) and Public Utility. System Level parachains would perform the functions of balance, elections (both staking and Council), governance and identity. The creation of a System Level parachain should be a non-controversial process, as functions are already handled by the Relay Chain.
Similarly, there are some services that are deemed fundamental and of public benefit. These are the projects that add new functionality and value to the Polkadot network. Examples of potential public utility parachains are bridges (exchange interfaces to other blockchains), generic asset chains, or a chain that supports the execution of smart contracts. These parachains would have the Relay Chain as their native unit of account, so DOT for Polkadot or KSM in the Kusama network.
This process would guarantee a slot for those projects that would otherwise risk being underfunded, as other teams would use the infrastructure without dedicating resources to it, i.e. the “free-rider” problem.
In this way the Relay Chain would only validate state changes of the various parachains, leaving all other functionality including transaction functionality within the parachains. This would make the Relay Chain even more resilient, increasing the security of the entire network and making it more efficient.
This possible process of architectural evolution is not included in the parachain roadmap recently published by Polkadot. However, in some cases it could delay the auctions for independent parachains, thus slowing down their release into the mainnet.