Three key words to know about parachain: scalable, efficient and secure.
When compared to sharding scheme, parachain is proposed to be easier to scale and more intuitive, powered with more functionalities; it is not merely a decentralized application but is empowered with its own blockchain ecosystem; it is also more efficient and easier compared to cross-chain trading.
Background
The majority of the blockchain systems are composed of two essential components: consensus and state machine. The consensus component provides the security for the blockchain network, is the fundamental which differentiates blockchain system from a conventional software system. Whereas, the state machine supplies various functions to support the blockchain system. Most of the blockchain networks currently adopt one of the three main consensus mechanisms: PoW, PoS and DPoS. As to the state machine, the situation is different, every chain is embedded with a distinctive state machine because every chain is designed to serve a particular function. The nature of parachain is to share the consensus mechanism — ‘network security’ with the main network, and a blockchain developer will just need to build a state machine to fulfill the promise that the parachain is designed to make.
Why parachain?
Outsiders may think that the security of blockchain network can be ensured if a handful of super nodes are established, or to add some mining mechanisms on top of that. As a matter of fact, the most recent 51% attack to a blockchain network with PoW consensus mechanism tells the many of us that PoW is not absolutely safe. As to DPoS mechanism, the relative smaller number of nodes will induce a higher probability for conspiracy among validators (nodes), the intuition behind DPoS was in fact to improve blockchain performance with sacrifice of network security — a tradeoff between performance and security. As we may probably notice by now, a blockchain network security is not supported by just a few nodes, it requires contributions from a dedicated technical team to maintain and a proactive involvement of community members to increase the size of nodes throughout the whole network, thus the security of the network. The resources that committed to maintain the security of the network is enormous, and since every public blockchain is isolated, the security resources from one network can not be reused to secure another network. A parachain is designed to share the consensus mechanism of the main chain and therefore the security of the main chain.
What is parachain?
Parachain (Parallel Blockchain) is a simple and scalable blockchain whose ‘security’ is provided by the main chain as it adheres to the consensus mechanism of the main chain. The relationship between a parachain and its main chain can be independent but also interdependent. A parachain can have its super nodes and state machine, but its security is supplied by the main chain, the transaction data and hash data on the parachain will be eventually kept on the main chain.
The main chain will ensure the security for its parachain, it also serves as a bridge to connect parachains for cross-chain interoperability, in this way the parachains and the main chain form a complete ecosystem. The best example can be seen in the league of royalty points where every business organization will have its own blockchain to issue its own royalty points, but the points are highly iliquid and not interoperable, just like the traditional point market. The existing problem in the point market is that points issued by a business entity can not be used in other business entities. The introduction of parachain can solve this problem, if every business organization incorporates a parachain to issue points individually and, through the main chain, they can exchange their points. For a singular blockchain, it is difficult to set up and develope the ecosystem. For a muti-chain blockchain with many parachains, the security resources are shared and security is reinforced, but more importantly the parachains are connected and interactive.
The nature of parachain
One of the key notion for parachains are that they function independently, however they are connected among each others through the bityuan main chain. There is a clear boundary among the parachains, they all can process transactions at once without conflicting with other parachains.
Conventionally, transaction is validated by each node before they are put into the block. Suppose now there are 10 parachains inherently different but are all attached to bityuan main chain, the great thing about this is that these 10 parachains can execute transactions inter-dependently and simultaneously without fear of collision, which improves the ‘transaction per second’ magnitude by 10 times. Perhaps an analogy would offer a better insight, suppose initially there is one road connecting point A and B with a traffic capacity 2,000 per hour. Now, the government decides to add 10 more roads connecting point A and B, which enables the traffic capacity to increase 10 times.
Parachains are attached to bityuan main chain, sharing the security resource from the security pool provided by bityuan main network, without the need to provide its own. Decentralized applications can be implemented on parachains, which is desirable. Because this enables developers who do not have much blockchain knowledge, to build use-cases on top of parachain. This is also what bityuan aims to do — allowing more to build blockchain applications with the least obstacles.
Every parachain can define its own functionality. When a bug is detected, the main network can easily implement upgrade to overly the bugged parachain, without inflicting the main chain.
Another pain point for blockchain in general is that the data contained in a blockchain is in a serial of events, therefore it is obligatory to download all the data to be able to validate the authenticity of the blockchain. Whereas, to validate a parachain, it is enough to just download the data which is relevant with this particular parachain.
In the bityuan network, a parachain is incorporated with an independent wallet and blockchain explorer. On top of that, a parachain can launch various blockchain projects within its own realm. Additionally, smart contracts can be created and executed. The more applications are built in the bityuan network, the more frequent will cross-chain trading be taken place, which leads to the prosperity of the ecosystem.
