CKB Mining Competition Round 4 Begins Sept 7!

Nervos Network
Sep 3 · 5 min read

Thanks to our community and all who participated in Round 3. Not only did it help us further stress test the network and provide valuable data and insights, but our community uncovered a critical bug that is now being fixed.

To thank everyone for participating in the development of Nervos CKB, the Nervos Foundation is sponsoring Round 4 of the Testnet Mining Competition—kicking off September 7 at 6:00 UTC and running through September 21.

Anyone can participate in the testnet mining, and potentially win a total of 9 million mainnet CKB tokens. Please join our Telegram(EN) if you have any questions.

The goal of Round 4 is to test our new hash function Eaglesong (reference the RFC and introduction). Eaglesong is the hash function for Nervos CKB proof-of-work, already deployed on testnet. We also have Eaglesong’s GPU miner (reference GitHub). Please note, that as our resources are limited, the GPU miner is only for Nvidia GPU. We are working on AMD GPU miner now. The Nervos team has no preference between Nvidia and AMD GPU.)

After the third round of our mining competition, we released an RFC (Request for Comment) to ready us for the fourth round. We gathered and reviewed comments from our community members, and have adapted the rules as follows:

Reward distribution

Total Rewards:
9,000,000 CKB mainnet tokens

All addresses that have mined at least 1,000 CKB will share this rewards pool and receive CKBytes in proportion with the block rewards produced by each address.

Start: September 7th 6:00 AM (UTC) UNIX Timestamp: 1567832400
End: September 21th 6:00 AM (UTC) UNIX Timestamp: 1569042000

Competition Process

9.7 5:00 AM UTC, release CKB testnet v0.20.0 in Github. ONLY using this testnet version can participate in mining competition.
9.7 6:00 AM UTC, competition begin. Blockchain explorer will be ready in two hours.
9.21 6:00 AM UTC, competition is over. We will release the result within one day on this website.

How to participate
To start mining on CKB testnet, simply follow the steps outlined in the official guide, or see community-created tutorials on Nervos Talk. A CKB blockchain browser is also available to look up your mining rewards.

CKB-Mine-Lord website was created by a community member to show the rank of all the addresses—you can check it to get your real-time rank—the code of this website (for reference).

At the end of the competition, we will calculate block rewards mined by each address. The accumulated block rewards of each address during the competition will form a basis for CKB mainnet token rewards (testnet tokens gained by transactions will NOT be counted as block rewards).

Rewards will be distributed directly to respective addresses on CKB mainnet. Please exercise caution when managing your private key, as it will be your only means of claiming your CKB token rewards.


How are the block rewards in CKB different from those in Bitcoin?
For Bitcoin, the block rewards are fixed in each block you mine. For CKB, the total block rewards are fixed in each difficulty adjustment epoch. CKB consensus adjusts difficulty to adjust block time. When difficulty increases, there will be less blocks mined during one epoch, but block rewards in each block mined will be increased. And vice versa.

What is difficulty adjustment epoch in CKB?
On the current Nervos CKB testnet, we target difficulty adjustments at every four hours (In Bitcoin, the difficulty adjustmrnt happens every 2016 blocks, while the block interval is 10 mins). For more details please refer to our consensus RFC .

Why do the rewards only apply to addresses that mined at least 3,000 CKB testnet token ?
The native token CKByte represents state storage space on the Common Knowledge Base. A cell is the basic data structure in the blockchain, and you can put any arbitrary data in a cell. It requires 60 CKBytes to create a cell.

During mining competition phase ONE, 105,000,000 CKB testnet token were mined, and we expect the same amount of testnet token will be mined in round 4. Given the rewards of 9,000,000 CKBytes, it requires you to have at lease 700 CKB testnet token mined to be able to receive the 60 CKBytes rewards. We add some buffer and require at least 1,000 CKB testnet token to receive rewards.

After mining a block, how long does it take to receive the block rewards?The block rewards from Block N will be received in Block “N + 11” (about 3 minutes) via Cell Base Transaction. This design related to our two-step transaction confirmation, if you are interested please check our consensus RFC .

What is Eaglesong? Is an Eaglesong miner available?
Eaglesong is a new hash function developed specifically for Nervos CKB proof-of-work. It is also suitable in other use cases where a secure hash function is needed. The design criteria includes novelty, simplicity and security. Here is the article written by the designer Alan and the RFC. We do have a miner, but it currently only supports Nvidia Card.

How do we know the value of token?
There are 33.6 billion CKB mainnet token in genesis block. For more detail check our token sale update.

Things to Note

  • This competition is the fourth in a series. We may have future rounds and the rules may change.

Terms and Conditions

  • Due to US regulation, US citizens and US entities are excluded from this competition.


  • There may be significant risks involved in cryptocurrency related activities. You may lose all of your investment. Tokens involved might have high volatility. Nervos Foundation will not be liable for any potential loss, financial or otherwise.

Interested in learning more about Nervos?
Explore our website and community: Forum Telegram Twitter Reddit Github

Nervos Network

The Nervos Network is a public blockchain ecosystem and collection of protocols aiming to solve the current challenges facing blockchains like Bitcoin and Ethereum today.

Nervos Network

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Official account for the Nervos Network.

Nervos Network

The Nervos Network is a public blockchain ecosystem and collection of protocols aiming to solve the current challenges facing blockchains like Bitcoin and Ethereum today.

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