How Stratum V2 and Merge-Mining Empower Miners: A Q&A with DMND and RootstockLabs

In a groundbreaking move, DMND and RootstockLabs have joined forces to integrate Stratum V2 with merge-mining, giving Bitcoin miners unprecedented control over block template construction and sidechain rewards. This partnership aims to further decentralize mining by allowing miners to independently manage merge-mining commitments for Rootstock (RSK) without relying on pool intermediaries. Below, we answer key questions about this development.

What is the partnership between DMND and RootstockLabs about?

DMND and RootstockLabs announced a new feature that leverages Stratum V2 to enable miners to handle their own block template construction while also selecting and including merge-mined block commitments from the Rootstock (RSK) sidechain. Traditionally, mining pools controlled these decisions, but this collaboration shifts power back to individual miners. By integrating Stratum V2, miners can now directly claim sidechain rewards in rBTC—Rootstock's Bitcoin-backed token—without revenue sharing or pool custody. This marks a significant step toward decentralizing the Bitcoin ecosystem, as it reduces reliance on centralized pool infrastructure.

What is merge-mining and how does it work?

Merge-mining allows multiple blockchains to reuse the same proof-of-work (PoW) from a set of miners. In this process, a child chain (like Rootstock) structures its block headers to include the parent chain's (Bitcoin's) header data. Specifically, the child chain's block header hash is embedded within a parent chain block—usually in the coinbase transaction. The child chain's software validates part of the parent chain's blocks during verification. Miners on the parent chain can then mine multiple blockchains simultaneously by including blockheader commitments in their coinbase transactions. When a block is found for the parent chain, it also applies to all child chains, earning miners rewards from both chains without additional energy costs.

What is Stratum V2 and why is it important for merge-mining?

Stratum V2 is an upgraded mining protocol that gives miners more autonomy over block template construction. Unlike its predecessor, Stratum V2 allows miners to choose which transactions to include in a block, rather than relying solely on the pool's template. For merge-mining, this means miners can independently decide which sidechain block commitments to incorporate. DMND and RootstockLabs' integration extends this capability to include Rootstock merge-mined blocks. By empowering miners with template selection, Stratum V2 reduces the risk of centralization caused by pools having too much control. This is crucial for maintaining Bitcoin's decentralized ethos, especially as merge-mining becomes more common.

How does this new feature improve decentralization of Bitcoin mining?

The feature enhances decentralization by shifting control from mining pools to individual miners. With Stratum V2 enabled for merge-mining, miners can now construct their own block templates and include sidechain commitments without pool mediation. This eliminates the need for pools to aggregate hashrate and dictate block content, which historically concentrated power. Additionally, miners receive rBTC rewards directly on the Rootstock sidechain, bypassing pool custody and revenue-sharing models. While some worry that merge-mining could centralize hashrate if one sidechain dominates, this integration tests such dynamics in practice. Alejandro De La Torre, CEO of DMND, states: "The miner controls the merge mining and the miner gets paid for the merge mining. More delegation of control to miners is our key support for further decentralisation of the Bitcoin ecosystem."

What specific benefits do miners gain from this integration?

Miners gain three key advantages: autonomy, direct rewards, and reduced counterparty risk. First, they can independently choose which Rootstock block commitments to merge-mine, allowing them to optimize for fee income or strategic preferences. Second, rewards are paid in rBTC directly on the sidechain, meaning no pool intermediary handles custody or distribution—miners receive their full share without fees. Third, this structure eliminates reliance on pool policies, which can change arbitrarily. DMND's infrastructure supports this seamless transition, enabling miners to claim rBTC while maintaining standard Bitcoin mining operations. For smaller miners, this levels the playing field, as they can now participate in merge-mining without needing large pools to manage the complexity.

Are there any potential risks or downsides to this approach?

While the integration promotes decentralization, it could also have opposite effects if not carefully managed. For instance, if a single sidechain like Rootstock becomes dominant, miners might concentrate hashrate on merge-mining that sidechain, potentially centralizing around its ecosystem. Additionally, the added complexity of managing block templates and sidechain commitments may discourage smaller miners unless adequate software support exists. However, the partnership provides a real-world test of these dynamics, allowing the community to assess whether the benefits outweigh the risks. Alejandro De La Torre emphasizes that giving miners more control is inherently positive for decentralization, but the market will ultimately determine the impact.

What did Alejandro De La Torre, CEO of DMND, say about the partnership?

Alejandro De La Torre, CEO and Co-Founder of DMND, highlighted the miner-centric philosophy behind the collaboration. He stated: "The miner controls the merge mining and the miner gets paid for the merge mining. More delegation of control to miners is our key support for further decentralisation of the Bitcoin ecosystem." This quote underscores DMND's commitment to empowering miners by removing pool intermediaries. According to De La Torre, the integration allows miners to directly manage both their Bitcoin block templates and Rootstock merge-mining commitments, ensuring they retain full authority over their revenue streams. He views this as a critical step toward a more resilient and decentralized mining landscape, where individual miners have agency over their operations rather than being subject to pool policies.