PChain MVP Review

by ZebraCrossing

This article will analyze PChain MVP (or better known as prototype, because Dr. Feng do not consider this as MVP). I have seen the video live test of PChain prototype. It is amazing, it is working, and a live demo how to run a smart contract with smart data (Oracle). It is actually much better than a lot of so-called MVP, for example, Quarkchain MVP (private testnet) has only 5 nodes while PChain prototype has 32 nodes.

What is PChain? PChain is the first native multichain system that supports EVM in the world, making large scale blockchain applications possible.

PChain = Zilliqa + Polkadots + Rootstock + Matrix

Please read my earlier articles if you are new to Pchain as this article is only attempt to analyze the prototype shown in the video.

All the screenshots shown below are captured from the video.

Analysis

PChain is using a novel consensus algorithm called PDBFT, P stands for PChain, D is distributed. The more and more popular PBFT can hardly support more than 20 nodes. The communication cost of PBFT is n-squared.

Using a novel PDBFT algorithm developed by Dr. Feng Cao, the communication cost is reduced from n-squared to n and even log(n), this is a major break through, and allows many nodes to be used in consensus and thus makes decentralisation possible. It achieved this break through using aggregate signature algorithm, which is a totally new algorithm designed to integrate within the new design of PChain. This makes possible high consensus speed with even thousands of nodes as validators (which is impossible when using PBFT algorithm).

The demo shows PChain explorer with one main chain and two child chains running live. The transactions is very fast, though no information is shown what is the current TPS. There are 32 validators for main chain and 16 validators for child chains. The validators are shared between the main chain and child chains.

PChain Prototype Explorer - Showing 1 main chain and 2 side chains.

PChain main chain with 32 validators and child chains each with 16 validators.

Pchain TXs

Smart Contract with smart data extension

For current Ethereum smart contract, the data provider needs to continually push the new data into smart contract, which is costly (gas price everytime it push data into smart contract), and inefficient. It need to wait for new block generation. PChain designed a new mechanism called smart data to solve this issues in Ethereum smart contract.

Dr Feng shows how smart contract with smart data is achieved in this demo. He is using a smart contract for a World Cup Casino 2014 test with Red and Blue team. With using smart data extension, the smart contract can feed data from an external source, in this example www.fifa.com. The demo shows how to write a smart contract with smart data feed from www.fifa.com. Also shown is how debugging of the smart contract with the smart data.

By using smart data, now the smart contract can instead pull data from external Oracle source rather than push by data provider. A totally new concept which is really novel and it will save cost and improve efficiency significantly. New applications are now possible with this smart data extension which is virtually impossible with Ethereum.

Sample source code of World Cup Casino smart contract using Solidity with smart data extension

Assembly code of the smart contract.

Debugging the smart contract

Results fed from www.fifa.com

Summary

Dr Feng shows us a live prototype of PChain working flawlessly with very fast transactions with one main chain and two child (side) chains (PChain explorer). A total of 32 validators (nodes) are used using a novel PDBFT consensus algorithm which is a lot more efficient than PBFT algorithm. N vs N-Square. A live demo was shown how to build a simple smart contract which can feed data from external source, www.fifa.com, in the example shown. And show in details how the debugging of the smart contract and how the results is derived. Do note that the very hype Quarkchain only has 5 nodes in their private testnet demo.

This live demo is actually 100% qualify to be called a live private testnet and much better than many other projects' testnet. It shows how solid is the PChain team. Their prototype already a lot better than many MVPs. PChain will be a game changer for blockchain with the smart data extension, and the ability to support native EVM, and cross chain capability of BTC, BCH and ERC20 tokens (do note cross chain capability is not implemented yet in the demo).

References

1. https://pchain.org/
2. https://t.me/pchain_org
3. PChain MVP (testnet) Demo