Most miners join a mining pool. The pool sends them work over a protocol called Stratum.
The problem with Stratum V1
- Unencrypted: internet providers can see shares and estimate a miner's hashrate. Attackers can hijack hashrate.
- The pool picks every transaction. A few big pools therefore decide what gets into blocks, a censorship risk.
Stratum V2's answer
- Encryption and authentication between miner and pool.
- Job declaration: miners can build their own block templates, so transaction selection moves back to many miners.
- Efficiency: binary messages use less bandwidth and reduce latency.
Why it matters
Pools are needed to smooth income, but they concentrate decisions. Stratum V2 keeps the payout benefit while spreading the power, strengthening censorship resistance. Adoption is gradual and voluntary.