Nervos CKB Testnet Mining Competition Round 4 Request for Comment

With the third round of the Nervos CKB mining competition complete, we want to express our sincere gratitude to the community, and all that participated.

We would like to remind our community that the proof-of-work testnet is still a “wild-west” with all sorts of craziness — being of course very different from how CKB and other mainnets like Bitcoin operate. These unexpected dynamics that sometimes can not be predicted theoretically, are exactly what the testnet is for.

The goal of Round 4 of our testnet mining competition is to test our new hash function— Eaglesong, here is RFC .

If you have any comments, please reply on the Nervos forum. The final rules will be released before the competition.

Nervos CKB mining competition phase 4 RFC

Total rewards: 9 ,000,000 CKB main net token
Time: Sept 7th 6:00 AM (UTC) - Sept 21th 6:00 AM (UTC)
Reward distribution:
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.


  • 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.
  • What is the difficulty adjustment epoch in CKB?

    • On the current Nervos CKB testnet, we target difficulty adjustments at every four hours (In Bitcoin, the difficulty adjust happens every 2016 blocks, while the block interval is 10 mins). For more details please refer to our Consensus RFC.
  • Why do the community pool rewards only apply to addresses that mined at least 1,000 CKBytes testnet token?

    • The native token CKByte represents state storage space on the Common Knowledge Base blockchain. A cell is the basic data structure in the blockchain, you can put any arbitrary data in a cell, and it requires 60 CKBytes to create a cell.
    • During two weeks’ period, we expect to have around 84 epochs and 1,250,000 block rewards for each epoch with a total of 105,000,000 CKB testnet token expected to be mined. Given the 3M total CKBytes community pool rewards, it requires you to mine at least 700 CKB testnet tokens in order to receive 60 CKBytes (round up to 1,000 CKB)
  • 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.
  • What is Eaglesong? Any 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 were exactly those described above — novelty, simplicity and security. Here is the article written by the designer Alan and the RFC.
    • Also now we already have miner. But it only support Nvidia Card. Please note that for now, the Nervos team is working on Layer 1 CKB. As our time and energy is limited, the GPU miner is only for Nvidia GPU. The Nervos team has no perference over Nvidia or AMD GPU.
  • Is there any mining pool yet?

    • Nervos foundation does not have a plan to design a mining pool. It will be designed by our community, so please check our community updates.
  • Is there any way I can get some testnet token.

    • Now we have a faucet to get testnet token. But note that during the competition we only count block reward, not balance. So testnet token from the faucet will not interfere with the result of competition.
  • Is there any wallet for CKB?

    • We have a Nervos CKB wallet called Neuron(beta). You should run a node while using Neuron. Note that Neuron is under developing so it might lose data.

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