What XBT is · Bitcoin on BLAKE2b

The fork

On 30 August 2026, at block 961,640, this chain stopped hashing with SHA-256 and started hashing with BLAKE2b-256. Blocks from that height carry a 164-byte header instead of Bitcoin's 80-byte one, which is why SHA-256 mining hardware cannot work here and why software has to be built for it.

Everything below that height is Bitcoin's: the same blocks, the same transactions, the same balances at the same addresses. Above it the two chains go their own way. Coins mined here are quoted as XBT to keep the two apart in writing and on exchanges.

What did not change: 21 million coins, the halving schedule, a 3.125 XBT subsidy at this height, ten-minute target spacing, retargeting every 2016 blocks, and the script rules your wallet already understands.

Addresses: the one real trap

Never use an address that holds real BTC. Because history is shared to block 961,640, a key that controlled coins on Bitcoin controls the matching coins here. Mining or receiving XBT to it publishes activity tied to your bitcoin address, and confuses every wallet that tries to read both chains. Make a wallet you use only for XBT.

This cuts both ways: if you held bitcoin before the fork, the same balance exists here, at the same address, and only your key can move it. Moving it means exposing that key to this chain's software, so treat it as you would any other claim of forked coins and decide carefully.

How mining works here

Most of this network's hashrate runs DATUM: the miner's own node builds the block template, and the pool only issues the coinbase split and verifies shares. It puts transaction selection back with miners rather than with a handful of pool operators, which was much of the point of changing the proof of work in the first place.

Pools that still build every template themselves, and hold rewards in their own wallet, are the exception here rather than the rule — and the direction of travel is away from them: Lazarus is retiring its own hosted stratum so that every block it finds is built by the miner who mined it. The galaxy map reads every block's coinbase and shows which pools do which, straight from the chain.

How pools pay here

Because rewards are paid inside the coinbase of the block that earned them, a payout and a block are the same event: no pool holds a balance for you, and nothing is owed if a pool disappears overnight. Each pool sets its own split and window — the Lazarus Pool site documents the one it uses.

The long coinbase maturity soft fork

From block 973,440 until block 979,920 (about 5 November 2026), Bitcoin Knots 29.4.2 requires newly mined coins to wait 6,480 blocks before they can be spent, instead of the usual 100. It is temporary, and its purpose is to make hit-and-run mining — arriving for a difficulty dip, dumping the reward, leaving — unprofitable, while miners who stay are unaffected.

If you mine: Payouts arrive in the coinbase exactly as before and are yours on chain immediately; they simply cannot be spent until they reach 6,481 confirmations.
If you run a node: Upgrade to 29.4.2 or later. An older node accepts blocks the network rejects, follows dead chains, and if it builds your templates, everything it mines is wasted.
After block 979,920: The rule lapses and maturity returns to 100 blocks. Coins mined inside the window unlock as they reach 6,481 confirmations.

Two further steps have been discussed publicly by the Knots authors: longer maturity still, and withholding rewards for blocks produced by pool stratum rather than by a miner's own node. Neither is in force. Read the proposal.

Holding XBT

Two practical options today:

An Electrum wallet, pointed at a server for this chain: Fast, no sync, no disk. Use our public server at electrum.lazarus-xbt.xyz:50002:s (SSL, protocol 1.8) with a wallet made fresh for XBT.
Your own node: Bitcoin Knots 29.4.2 built for BLAKE2b, with its own wallet. Slower to set up, answerable to nobody. The node directory has builds and a reference config.

Glossary

BLAKE2b: The hash function this chain's proof of work uses instead of SHA-256.
Coinbase: The first transaction in a block, which creates the reward. Pools here pay miners inside it, so a payout and a block are the same event.
DATUM: A protocol where the miner's node builds the block template and the pool only sets the payout split.
Gateway: The DATUM software a miner runs beside their node; their own miners connect to it.
Prime: The pool-side server a gateway talks to; each pool runs its own.
TIDES: A payout scheme built on a rolling window of accepted work, paid in each block's coinbase.
Window share: Your fraction of the work in the current window — what the next block would pay you, which is not the same as your hashrate.
Maturity: How long a coinbase output must wait before it can be spent: normally 100 blocks, currently 6,480 under the soft fork.