Polkadot is an imminent multi-chain framework platform – similar to Cosmos – designed to facilitate interoperability and scalability of blockchain that can fit into its "Relay Chain". Polkadot is an ambitious project that uses a form of proof-of-stake (PoS) consensus for the broader blockchain ecosystem that are connected to it and is expected to launch officially in the third quarter of 2019.
It is important to note that Polkadot allows data structures, outside the blockchain, to connect to the network as "parachutes". Originally conceived by Gavin Wood – creator of the Solidity programming language -, Polkadot is a heterogeneous multi-chain structure in which the parachutes operate through a trust -thin federation structure.
The scalability problems of blockchain networks are well documented and platforms such as Polkadot are striving to become the next generation of networks that promote scalability and advanced interoperability through the expansion of public blockchain design concepts and the standardization of data transfer.
The design of Polkadot
Polkadot explicitly identifies three main areas to which current blockchains struggle to realize their full potential to provide practical applications:
- interoperability
- scalability
- Shared security
Polkadot uses a relay chain that acts as a hub through which the parachutes connect and co-ordinate the consent as well as the transfer of messages and data between the parachutes. In particular, both public and public blockchains can connect to the network, with the possibility of authorized chains to isolate themselves from the rest of the system while maintaining the possibility of transferring data to other chains and exploiting network security.
Parachutes can be blockchains or other data structures that fit into the relay chain for security and interoperability in pools with other chains. However, they must meet the following criteria to be compatible with the Polkadot network:
- It can form tests of light and compact customers
- It must be a method for a large number of independent authorities to authorize a transaction (for example, signature Schnorr).
The parachains process their own transactions, which allows the network to scale on the basis of simultaneous and independent processing of parachain transactions, which are guaranteed through the broadest consensus of the network.
Polkadot's consensus is strongly inspired by Tendermint and HoneyBadgerBFT, but it uses PoS as the main method to encourage validators to be honest in the network.
Read: Beginner & # 39; s Guide to Tendermint: Byzantine fault tolerant blockchain engine
Polkadot can also form "bridges" with other chains that have their consent – such as Ethereum.
The lower layers of the Polkadot protocol are known as the Polkadot Runtime Environment and are common to all parachutes on the network. These 3 levels consist of the Wasm interpreter, consensus and networking.
The upper layers are unique to each connected parachute. Substrate – from Parity Technologies – is the first implementation of the Polkadot Runtime Environment (PRE). The parachutes will be written using PRE, which is built on the Web3 technology stack.
An important aspect of Polkadot is that it uses the Libp2p network stack and is the first real use of its Rust implementation.
The dynamics of how Polkadot works are complex, so it is better to visualize the platform through the four main roles involved in the ecosystem.
- validators
- Nominators
- Collecting
- fishermen
validators
The validators complete the blocks in the Polkadot network and play the most critical role in the ecosystem. Validators are required to run the full forwarding chain client and must participate in a significant "link" (in the native DOT token) to qualify. However, validators can nominate other validators to act in their place.
The validators receive blocks of candidates from the colliders – which propagate the selected blocks to the validator subgroups from the parachutes – and finalize the blocks on the relaunch chain through a deterministic selection process and a final ratification validation cycle.
Nominators
The names are parties that also hold a stake in the network, but act as a mechanism to select valid validators through their link to the constraint of a selected selector. Their role is very direct and helps to strengthen the security of the relay chain.
Collecting
Collectors work on the parachute level rather than directly with fixing the relay chain. They collect transactions from the parachutes, produce a test along with an unsealed block and send it to the appropriate validator in charge of finalizing a parachute block. The Polkadot white paper notes that the role of collators can evolve and may eventually be contracted to work closely with specific validators to verify blockages from some parachutes.
Collators can also work to demonstrate malicious behavior to network validators as an additional level of security. The general role of collators is similar to the work of miners in the PoW blockchains.
fishermen
Fishermen are independent of the block verification process and look for malicious behavior on the network that report to validators on invalid validators. They are motivated as "bounty hunters" who seek substantial one-off rewards by demonstrating that a forced party (ie, a validator or collector) has acted maliciously outside the rule set.
Fishermen also publish small bonds on the network, however. This is to prevent Sybil attacks, but it is not at the height of the validators and can be withdrawn at any time.
Image Credit – Polkadot Whitepaper
Polkadot reaches a standardized communication through the network through its interchain communication protocol. The transactions between the parachutes or between the parachute chain and the relay chain are completely asynchronous and all data transfers (even between parachutes) refer to the relay chain.
Blockchains "connected" to Polkadot instead of directly connected as a parallelepiped can exploit the standardized intercommunication of the network without sacrificing their consent. However, these chains renounce the shared state and security guarantees of the Polkadot network. Ethereum will be the first example of such a bridge on the platform.
The role of DOT tokens and polkadot governance
Polkadot uses a chain governance model entirely controlled by the relay chain stakeholders. Interested parties (ie validators) put the native DOT token into play and can control everything from direct protocol updates to bug fixes.
Like other PoS consent models, the native token is used for bonding and to incentivize the validators to act honestly through a financial participation in the authenticity of the verification process. In addition, the parachutes connect to Polkadot through gluing and can be removed by withdrawing their mail from the network.
Polkadot is currently in its POC-2 testnet phase, where testDOT was used to update the protocol from the POC-1 network and introduced several other features, including the use of the Libp2p Rust implementation.
On-chain governance is a fascinating concept and is not only used by Polkadot, but by other existing networks such as Tezos and Decred.
Polkadot applications
Since Polkadot makes no assumptions about the parachutes connected to the network, it offers developers a wide range of flexibility to create application-specific blockchains such as privacy-oriented ones or some that explicitly focus on some of the first developments.
Polkadot is also designed to facilitate faster innovation cycles. The characteristics of a parachen can be exploited on another, sharing the innovation between chains and not simply the token transfers as the only form of interoperability. The parachutes are also free to focus on creating applications rather than focusing on their own security. The parachutes explicitly designed to operate within Polkadot are part of the broadest security in the pool, creating a crucial abstraction of one of the most complicated components of blockchain networks for developers.
An intriguing example provided by Polkadot is the possibility for users of a decentralized exchange on a parachain to deposit BTC on the exchange using zero knowledge tests (ZKP) using a ZCash parachain.
The potential applications of multi-chain frameworks are huge and should help promote much more experimentation with new technologies born of pure interoperability power. However, consensus – in particular the PoS – is complex and difficult to design and has yet to be demonstrated on a large scale in a decentralized network for a considerable time, especially in a multi-chain environment.
Polkadot offers another promising look at how the next generation of blockchains will be, and could prove to be a gravitating environment to allow public and authorized blockchains to come together and benefit each other.