• The Stratum V2 Protocol: What It Changes for Miners
  • The Problem With Stratum V1
  • How Stratum V2 Fixes This
  • The Revenue Difference
  • The Censorship Resistance Win
  • Key Takeaways

§The Stratum V2 Protocol: What It Changes for Miners

Stratum V2 is the next generation of Bitcoin’s mining pool protocol. It’s been in development for years, and by 2026 has seen significant deployment among major mining pools. Understanding what it changes reveals important improvements in mining efficiency, censorship resistance, and hashrate market dynamics.

§The Problem With Stratum V1

Stratum V1, which has powered the vast majority of Bitcoin mining since 2012, has a structural vulnerability: the pool determines which transactions go into a block. Individual miners submit “shares” — partial proof of work — and the pool assembles the actual block.

This means: the pool can censor transactions. If a pool decides not to include certain transactions, miners connected to that pool can’t include them. In theory, a large pool could refuse to process transactions from certain addresses — creating soft censorship.

This was a theoretical concern for years. It became relevant when certain pools’ hashrate exceeded 20% of network total.

§How Stratum V2 Fixes This

Stratum V2 introduces “BetterHash” — the ability for individual miners to select their own transactions. Instead of the pool deciding the block template, the pool sends the previous block header, and the individual miner constructs the transaction set.

The pool still receives shares and distributes rewards. But the miner — not the pool — chooses which transactions go into their blocks. Pool hashrate still contributes to the pool’s total, but individual miners control transaction selection.

§The Revenue Difference

In Stratum V1, miners receive shares based on the probability they’re finding a block. Pools typically charge 1-4% fee and handle transaction selection. In Stratum V2, miners retain control over transaction selection but pools still handle the share accounting and reward distribution.

For large mining operations, Stratum V2 enables a new revenue model: miners can include their own transactions (perhaps proprietary arbitrage across exchanges) while still contributing to a pool’s collective hashrate. This could offset pool fees entirely for sophisticated operators.

§The Censorship Resistance Win

The primary benefit is political: even if a pool’s operator were compelled by regulators to exclude certain transactions, their connected miners could still include them. The hashrate contribution and censorship resistance operate independently.

This matters most for mining in jurisdictions with heavy regulatory oversight. A Chinese mining operation (if such still existed) contributing to a pool couldn’t be compelled to censor — because the pool never sees the miner’s transaction selection.

§Key Takeaways

• Stratum V1 gives pools control over transaction selection — potential censorship vector
• Stratum V2 gives miners control over their own block templates while pooling hashrate
• Major pools deploying Stratum V2 improves Bitcoin’s censorship resistance materially
• Sophisticated miners can include proprietary transactions while pooling, potentially offsetting fees
• The protocol change is invisible to end users but structurally improves Bitcoin’s neutrality properties

⚡ If this was useful, a zap is always welcome. tomford@rizful.com