BTCB2 (Bitcoin BLAKE2b): what it is and how to mine it
BTCB2 (Bitcoin BLAKE2b, also XBT on exchanges) is a Bitcoin fork that split from the main network on 8 August 2026 and since 30 August 2026 has been mined with the BLAKE2b algorithm instead of SHA-256. Bitcoin ASICs therefore cannot mine it – it is mined on machines originally built for Siacoin, such as the iBeLink BM-S3+ or Goldshell SC6 SE. The reward is 3.125 BTCB2 per block and 1 TH/s currently earns approximately 131 Kč a day. Until the beginning of November 2026, however, a temporary freeze on mined rewards applies.
Summary
- BTCB2 shares Bitcoin's entire history up to block 961,631. Anyone who held BTC before the split also has BTCB2 on the same addresses.
- The chain runs on Bitcoin Knots nodes, maintained by Luke Dashjr. The parameters (21 million coins, 10-minute blocks, halvings) remained the same as Bitcoin's.
- It is mined with Blake2b-Sia ASICs. The same machine can mine either BTCB2 or Siacoin – not both at once.
- Between blocks 973,440 and 979,920 a temporary reward maturity of 6,480 blocks (about 45 days) applies. The coin trades on only a few small exchanges.
How BTCB2 came about
It started with a dispute over the BIP-110 proposal. It was meant to temporarily restrict storing non-monetary data in the Bitcoin blockchain – for example inscriptions or large OP_RETURN outputs. Activation required 55% of miners to signal for it. Support, however, stalled at around 2.5%.
The minority that enforced the BIP-110 rules split from Bitcoin on 8 August 2026 with block 961,632. But almost nobody mined its chain: only eight blocks were created in 22 days. That is why the developers around Bitcoin Knots replaced the mining algorithm with BLAKE2b from block 961,640 (30 August 2026). Bitcoin's SHA-256 machines thus dropped out of the chain, and new miners arrived with machines from the Siacoin ecosystem.
The name is not consistent. Exchanges and pools use BTCB2, XBT or BIP110, while Luke Dashjr himself simply calls the chain Bitcoin. XBT is also the international code for bitcoin, so beware of confusion.
BTCB2 network parameters
| Parameter | BTCB2 | Bitcoin for comparison |
|---|---|---|
| Algorithm | BLAKE2b (from block 961,640) | SHA-256 |
| Block time | approx. 10 minutes | approx. 10 minutes |
| Block reward | 3.125 BTCB2 | 3.125 BTC |
| Next halving | block 1,050,000 | block 1,050,000 |
| Difficulty adjustment | every 2,016 blocks | every 2,016 blocks |
| Maximum supply | 21 million | 21 million |
| Node software | Bitcoin Knots (current version with BTCB2 rules) | Bitcoin Core, Knots and others |
| Network hashrate as of 18 October 2026 | approx. 42 PH/s (BLAKE2b) | – |
| Height on the morning of 18 October 2026 | block 977,828 | – |
We derived the network hashrate from the difficulty reported by B2Pool (5.94 billion). Because BTCB2 blocks were created faster than Bitcoin's in the first weeks, the chain is several thousand blocks ahead and the halving will come sooner here.
The 45-day reward freeze: what applies now
Since block 973,440 (22 September 2026), Bitcoin Knots has applied a rule that raised coinbase maturity – i.e. of block rewards – from 100 to 6,480 confirmations. Mined coins therefore cannot be spent for roughly 45 days. Ordinary transfers between wallets work normally.
The rule is limited to blocks 973,440 to 979,920. As of 18 October 2026, about 2,090 blocks remain until the end of the window, i.e. roughly two weeks – according to block explorers, the beginning of November 2026. The developers, however, have described it as the first of three steps, and the length of the period has already changed during development. A detailed analysis of why the rule was introduced and what it means for payback calculations can be found in the news item Bitcoin BLAKE2b freezes miners' rewards for 45 days.
How much a BTCB2 miner earns today
We recalculate earnings every hour based on network difficulty (B2Pool data) and the BTCB2 price, which today is 12 363 Kč. For 1 TH/s it is 131 Kč a day, about 0.0106 BTCB2 in coins.
| Miner | Hashrate | Power | Efficiency | Gross / day | Electricity / day at CZK 1.13/kWh |
|---|---|---|---|---|---|
| iBeLink BM-S3+ | 25 TH/s | 3,400 W | 136 J/TH | approx. CZK 3,270 | approx. CZK 92 |
| iBeLink BM-S3 | 19 TH/s | 3,100 W | 163 J/TH | approx. CZK 2,480 | approx. CZK 84 |
| Goldshell SC6 SE | 17 TH/s | 3,330 W | 196 J/TH | approx. CZK 2,220 | approx. CZK 90 |
| Goldshell SC5 Pro II | 14 TH/s | 3,300 W | 236 J/TH | approx. CZK 1,830 | approx. CZK 89 |
| iBeLink BM-S1 Max | 12 TH/s | 3,150 W | 263 J/TH | approx. CZK 1,570 | approx. CZK 85 |
| Goldshell SC5 Pro | 11 TH/s | 2,820 W | 256 J/TH | approx. CZK 1,440 | approx. CZK 76 |
| Goldshell SC Lite | 4.4 TH/s | 950 W | 216 J/TH | approx. CZK 575 | approx. CZK 26 |
Calculation as of 18 October 2026, without the pool fee. The figures look tempting, but read them with caution. During the freeze these are credited coins, not money in your account. The price comes from a few small exchanges with low liquidity, so a larger volume may not sell at it. And you pay for electricity every day, while you only get the coins after they mature.
How to start mining BTCB2
- Set up a new wallet just for BTCB2. Do not use addresses holding real BTC – the networks share history and there is a risk of transactions being replayed on the other chain. The basis is a wallet in Bitcoin Knots.
- Choose a pool. Some pools (e.g. B2Pool) accept connections via the standard Stratum protocol. Others, such as Lazarus Pool, work via DATUM – your own Knots node and a gateway through which the miner builds blocks themselves.
- Enter the pool's stratum address and your address in the miner's web interface, just as with other coins.
- After 10–15 minutes, check that the pool shows your hashrate and accepts shares. If it rejects all of them, the pool does not support the model or firmware.
- Follow reward maturation on the pool's blocks page or in a block explorer.
If you are setting up a machine for the first time, the general procedure can be found in the guide connecting an ASIC.
BTCB2 or Siacoin?
Blake2b-Sia machines can mine two different networks. But at any one time a miner sends work to only one pool, so it mines either BTCB2 or Siacoin. Today 1 TH/s works out at about 131 Kč a day on BTCB2 and 24 Kč on Siacoin. Siacoin, on the other hand, has a history going back to 2015, trades on big exchanges and its rewards are not frozen. You will find a comparison in the article Siacoin (SC).
Where BTCB2 is traded
According to sources from September 2026, BTCB2 is listed neither on CoinGecko nor on CoinMarketCap. It trades on a few small exchanges, for example NonKYC (under the ticker BTCB2) and SafeTrade (XBT, BIP110). The project itself describes the first exchange, Neoxa, as risky. The price has been very volatile from the start: from the first trades at around USD 80 it climbed to USD 1,799 on 5 September 2026 and by 21 September 2026 had lost over 80%.
Risks of mining BTCB2
- The rules change on the fly: the reward freeze came a month after launch, and the developers have announced further steps that they have not yet published.
- Low liquidity: small exchanges, a thin market and the risk that supply will outweigh demand once rewards are unfrozen.
- Concentration of hashrate: on 8 September 2026 one pool (AlphaPool) briefly had over 50% of the network's hashrate; it later committed to a 30% cap.
- A young network: there are few wallets, exchanges and services, and they appear and disappear quickly.
What next
- The 45-day BTCB2 reward freeze – what exactly has changed and where to follow developments.
- Miners for BTCB2 and Siacoin – all Blake2b-Sia machines with a calculator.
- ASIC miner hosting – running noisy machines (75–80 dB) at an industrial electricity price.
Sources
Frequently asked questions
Can I mine BTCB2 on an Antminer S19 or S21?
Do I have BTCB2 if I held bitcoin before the fork?
When will the BTCB2 reward freeze end?
Where can BTCB2 be sold?
Is BTCB2 the same as XBT?
This text was prepared with the help of AI. Facts, figures and procedures were checked by Yegor.
