YeeCo(YEE) PoC-5 Officially Released

3 min readNov 30, 2019

On November 29, the PoC-5 phase of the YeeCo public chain project was successfully completed and officially released, completed the development work of dynamic sharding, CRFG final determination, cross-sharding transactions verification and block reward.

Description

PoC-5 is described in the roadmap section of yeeroot project description:

PoC-5: Dynamic sharding、CRFG final determinism (2019–11)

Glossary

1.Dynamic sharding

Dynamic sharding is the process of expanding the number of shards in the blockchain system using the fragmentation scheme without stopping service. The expansion process should meet the requirements of decentralization, security and high availability.

In the implementation process, we need to pay attention to three aspects: first, the logic of data processing is different before and after the expansion of a specific height; second, during the transition period of expansion, it is easy to have different progress of expansion; third, we need to deal with the impact of the rollback of pow consensus on the expansion operation.

2.Multi-mining

When Multi-mining is performed on multiple chains according to a unified mechanism, the verification requirements of all chains can be satisfied, and the total hashrate consumption can be greatly reduced.

3.CRFG

YeeCo introduced the CRFG (Conditional Reward Finality Gadget), which establishes the absolute finality for the PoW consensus, and enables split-segment transactions to be split into independently verifiable sub- transactions to ensure high throughput.

The CRFG program contains the following points:

1.Separation between the consensus of the block generation and the deterministic consensus.

2.Select a set of voters based on the block generation to establish a deterministic consensus through PBFT.

3.Take a conditional block reward mechanism to solve the problem of nothing at stake attacks.

4.cross-sharding transaction

The cross-sharding transaction is essentially a cross-chain transaction. A transaction is split into two processes. The first process performs balance checking and balance reduction operations on one chain, and the second process adds balance operations on another chain. The two processes as a whole are an atomic operation.

Feature List

1.Address format

Yeeco address follows bip39 standard and uses 4096 coin type.

YeeCo addresses are encoded in bech32 format and use HRP.

2.Block reward

Miners in each new block will receive YEE rewards. The amount is calculated as follows:

block_reward = 50 / shard_count + transaction_fees

According to the conditional reward mechanism design, the block reward will be postponed until the miners have exercised all the voting rights granted by the new mining block.

3.CRFG

The yeeroot node can achieve final determinism, and the bidders of the final deterministic consensus rotate according to the block.

4.Cross shard transactions verification

The yeeroot node uses MMTP (Multi-merkle-tree-proof) technology to achieve strict verification of cross-shard transactions.

5.Sharding scalability

Yeeroot node achieves dynamic sharding.

6.Optimize block production speed

Block production speed increased to 30 seconds.

Limitations of version features and future work

To prevent final consensus from failing, it is recommended not to change the Authority key (used to perform CRFG voting). We will provide a secure way to change the Authority Key in subsequent work.