Stratum V2 is the next generation protocol for pooled mining. It increases security, makes data transfers more efficient, and reduces mining infrastructure requirements. It also introduces three new sub-protocols that let miners select transaction sets and improve decentralization by negotiating with pools.
Before Stratum V2, transaction sets were selected by pools. With this SV2 configuration they’re selected by individual miners, making the network more censorship-resistant. Miners run SV2 firmware, connecting to the SV2 proxy server. Miners can pick their transactions locally and negotiate them with an SV2 pool.
V2 introduces by-default encryption and NOISE protocol authentication, hardening the protocol against man-in-the-middle attacks.
The new Stratum optimizes data transfer size and frequency between miners, proxies, and pool operators, creating higher submission rates while reducing hash rate variance (miner payouts).
V2 improves logic and framework by letting miners and mining pools running V1 make incremental and modular improvements. These implementations can communicate via pool and client-side proxy translations with minimal tradeoffs.
New features further decentralize bitcoin by integrating distributed transaction selections into the protocol, letting end-miners build and select transaction sets and block templates.
By failing to precisely define Stratum V1’s specifications, we inadvertently created multiple implementations with varying semi-compatible dialects. Stratum V2 fixes this by defining its protocol parameters to ensure cross-compatibility between and pools and end-mining devices.
Stratum V2 specs authors are Pavel Moravec and Jan Čapek, in collaboration with Matt Corallo and other industry experts.