New YorkStratum V2 gains 75% of Bitcoin network hashrate.
Under V1, pool operators choose which transactions enter each block; Stratum V2 moves that selection to the individual miners doing the work.
Foundry’s 34.2% hashrate share is unchanged; Stratum V2 redistributes only who picks transactions, not who earns block rewards.
Sources: CoinDesk
WHY POOLS EXIST
Solo mining a Bitcoin block today is a lottery — even an industrial farm might wait years between wins. Pools aggregate hashrate so miners earn a steady proportional share of rewards instead of waiting for a jackpot. The tradeoff: the pool operator, not the miner, gets to assemble each candidate block.
THE CENSORSHIP SURFACE
Because a handful of pools control most hashrate, whoever pressures those operators can effectively exclude transactions from Bitcoin. OFAC-flagged addresses, mixer outputs, and sanctioned wallets have all been quietly filtered by some pools — a centralization risk Satoshi's design did not anticipate.
WHAT V1 LOOKED LIKE
Stratum V1, introduced in 2012, became the de facto protocol pools use to dispatch work. It is unencrypted, unauthenticated, and gives the miner only a Merkle root — the miner cannot see, choose, or even know the transactions it is securing.
WHAT V2 CHANGES
Stratum V2 adds end-to-end encryption (preventing ISP-level hashrate hijacking) and introduces a Job Declarator role that lets the miner — not the pool — build the block template. The pool still distributes payouts, but transaction selection is pushed back to the edges of the network.
WHY 75% MATTERS
A protocol upgrade only changes behavior once the majority of hashpower runs it. At 75% adoption, censoring a transaction at the pool level no longer reliably keeps it out of a block — some miner in the pool can include it anyway. The threshold turns censorship from a phone call into a coordination problem.
THE BROADER PATTERN
Bitcoin's threats have shifted from cryptographic to organizational. The hash function is unbroken; the elliptic curve is unbroken. What erodes the network is concentration — of pools, of ASIC manufacturing, of fiat on-ramps. Stratum V2 is the first major protocol response aimed squarely at the organizational layer.