TL;DR
- Cornell University researchers revealed that Bitcoin and Ethereum are far more centralized than their proponents claim
- The top four Bitcoin mining operations controlled over 53% of the network’s average mining capacity on a weekly basis
- Just three Ethereum miners accounted for 61% of that network’s average weekly mining capacity
- 56% of Bitcoin nodes run from data centers, compared to 28% for Ethereum, suggesting increasing corporatization
- The findings challenged the foundational narrative that cryptocurrencies are inherently decentralized
On January 18, 2018, as cryptocurrency markets were in the midst of one of their most violent sell-offs, a groundbreaking study from Cornell University quietly reshaped the conversation about the fundamental nature of blockchain networks. The research, led by prominent cryptocurrency expert Emin Gün Sirer, delivered findings that struck at the very ideological foundation of the crypto movement: Bitcoin and Ethereum, the two most celebrated decentralized networks, were not nearly as decentralized as anyone had assumed.
The Mining Centralization Problem
The study’s most striking revelation concerned mining — the computational process that verifies transactions and secures blockchain networks against attack. In theory, both Bitcoin and Ethereum are open systems where anyone with the right hardware can participate as a miner. In practice, the researchers found that mining power had become dangerously concentrated.
For Bitcoin, the top four mining operations controlled more than 53% of the network’s average mining capacity when measured on a weekly basis. This meant that just four entities held majority control over the network’s transaction verification process at any given time — a concentration of power that Bitcoin’s pseudonymous creator Satoshi Nakamoto had specifically designed the system to prevent.
Ethereum’s situation was even more concerning. The researchers found that just three miners accounted for 61% of Ethereum’s average weekly mining capacity. This supermajority concentration meant that a tiny group of actors held effective veto power over the entire Ethereum network, a finding that directly contradicted the community’s self-image as a paragon of decentralization.
Infrastructure Concentration in Data Centers
Beyond mining, the Cornell team examined the geographic and infrastructural distribution of network nodes — the computers worldwide running each blockchain’s software. The findings revealed a surprising pattern: 56% of Bitcoin’s nodes were operating from data centers, rather than from individual computers in homes or offices. For Ethereum, the figure was 28%.
Sirer noted that this data center concentration might indicate that Bitcoin had become more corporatized than its community liked to acknowledge. The image of a globally distributed network of individual enthusiasts running nodes from their personal computers was, at least in part, a myth. In reality, the infrastructure supporting the world’s most valuable cryptocurrency was increasingly housed in professional data centers operated by commercial entities.
Neither Network Superior
Despite the tribal rivalries that defined much of the cryptocurrency discourse in early 2018, the Cornell research declined to declare a winner. The group concluded that neither Bitcoin nor Ethereum “has strictly better properties than the other” when it came to decentralization. Each had its own vulnerabilities and concentrations of power, and neither could credibly claim to be the more decentralized system.
This nuanced conclusion was significant in a community that often treated decentralization as a binary virtue — you were either decentralized and good, or centralized and bad. The research suggested reality was far more complicated, with both networks exhibiting concerning levels of centralization in different areas.
The Ripple Comparison
The study also highlighted the case of Ripple as an instructive contrast. Unlike Bitcoin and Ethereum, Ripple made no pretense of full decentralization — a privately owned company oversaw the distribution of its coins and still held more than half of all XRP in existence. Yet the researchers noted that the concentration patterns in Bitcoin and Ethereum’s mining ecosystems weren’t entirely dissimilar in practice, even if they differed in structure.
Why Decentralization Measurement Matters
The Cornell study arrived at a critical moment. In January 2018, the total cryptocurrency market capitalization still exceeded $450 billion, with Bitcoin alone valued at roughly $193 billion. Hundreds of billions of dollars of value were secured by networks whose decentralization properties had never been rigorously measured. The lack of standardized metrics for assessing decentralization meant that investors, developers, and regulators were making consequential decisions based on assumptions rather than evidence.
Sirer and his team argued that meaningful discussions about the future of cryptocurrency required a more empirical approach to measuring decentralization. The distribution of coins, the governance of protocol upgrades, the geographic spread of miners and nodes — all of these factors contributed to how truly decentralized a network was, and none of them could be taken for granted.
Why This Matters
The Cornell decentralization study, published on January 18, 2018, forced the cryptocurrency community to confront an uncomfortable truth: the technology’s most celebrated virtue was more aspiration than reality. The finding that a handful of mining operations controlled majority hash power on both Bitcoin and Ethereum had profound implications for network security, governance, and the ideological narrative that had driven crypto adoption.
If wealth and power could pool in the hands of a few — whether through mining concentration, node corporatization, or token distribution — then the revolutionary promise of cryptocurrency was fundamentally undermined. The study’s legacy would echo through subsequent debates about mining pool dominance, the rise of ASIC manufacturers, Ethereum’s transition to proof-of-stake, and ongoing concerns about institutional capture of supposedly decentralized networks.
Disclaimer: This article is for informational purposes only and does not constitute financial advice. Cryptocurrency investments carry significant risk. Always conduct your own research before making investment decisions.