Bitcoin and Ethereum face a surprising centralization risk: a new analysis shows that just three entities could accumulate enough computing power or stake to materially influence how blocks are produced on each network. By contrast, Solana would need 19 entities to reach the same threshold, according to research published by Glassnode and Ark Invest on September 1.

What Does "Influencing Block Production" Actually Mean?

The study's findings warrant careful interpretation. The researchers emphasized that the ability to influence block production does not equate to direct control over a network. In Bitcoin's case, multiple individual miners contribute their computing power, or hash power, to a single mining pool. Similarly, in proof-of-stake networks like Ethereum and Solana, many users delegate their cryptocurrency holdings to validators who stake on their behalf.

This distinction matters because even when a mining pool or validator controls a large share of the network's total computing power or stake, the operator does not necessarily own all of the underlying resources. The actual miners or token holders retain some degree of agency, though their participation is channeled through a centralized intermediary.

How Does Blockchain Infrastructure Vary Across Networks?

The Glassnode and Ark Invest report also examined how decentralized each blockchain's underlying infrastructure actually is. The findings revealed significant differences in how each network distributes its nodes, or the computers that validate transactions and maintain the ledger.

• Bitcoin's Node Distribution: Bitcoin's nodes were found to be relatively evenly distributed geographically, suggesting less reliance on any single region or data center. Additionally, about 63 percent of all Bitcoin nodes operate through Tor, an anonymous communications network that adds a layer of privacy to node operations.
• Ethereum's Cloud Dependency: Ethereum showed a higher reliance on cloud infrastructure, with approximately 20 percent of all nodes running on Amazon Web Services. This concentration on a single commercial cloud provider introduces potential vulnerabilities if that service experiences outages or regulatory pressure.
• Solana's Data Center Concentration: Solana was found to run a substantial share of its network infrastructure through data centers, which may create geographic or operational bottlenecks compared to more distributed approaches.

Why Should Miners and Stakeholders Care About These Metrics?

The study's authors cautioned against oversimplifying decentralization assessments. Evaluating whether a blockchain is truly decentralized requires looking beyond just the number of entities involved in block production. A comprehensive view must also account for mining pool structures, staking delegation arrangements, the geographic distribution of nodes, and how infrastructure is physically operated and hosted.

For Bitcoin miners and Ethereum stakers, these findings underscore the importance of pool diversity. Miners who concentrate their hash power in a single pool, or stakers who delegate to a single validator, contribute to the centralization risk identified in the report. Conversely, spreading participation across multiple pools or validators strengthens the network's resilience.

How to Evaluate Blockchain Decentralization

• Mining Pool Concentration: Examine how many mining pools control the majority of hash power on proof-of-work networks like Bitcoin. A network where three pools control 51 percent of hash power is more vulnerable than one where ten pools share that power.
• Staking Delegation Patterns: On proof-of-stake networks, review how many validators hold the majority of staked assets. Fewer validators with larger stakes increase centralization risk compared to many validators with smaller stakes.
• Geographic Node Distribution: Assess whether nodes are spread across multiple countries and regions. Networks with nodes concentrated in one or two geographic areas face regulatory and infrastructure risks that globally distributed networks do not.
• Infrastructure Provider Diversity: Evaluate whether nodes rely on a single cloud provider or data center operator. Networks that depend heavily on Amazon Web Services, for example, face outage risks tied to that provider's operations.

The Glassnode and Ark Invest analysis provides a data-driven foundation for ongoing debates about blockchain decentralization. While Bitcoin and Ethereum remain the most established and widely adopted cryptocurrencies, the research suggests that their block production mechanisms are more vulnerable to concentration than commonly assumed. For network participants, miners, and long-term holders, understanding these structural risks is essential to evaluating the true security and resilience of the networks they rely on.