Decentralization is a key word in the blockchain world. However, which blockchains are really decentralized? Let's have a look at the number of nodes:
- Bitcoin is the most developed blockchain with 10304 nodes totally, which are mostly located in Europe, and particularly in Germany (18% of total)
- Ethereum distinguishes nodes from clients ("Node refers to a running piece of client software. A client is an implementation of Ethereum that verifies all transactions in each block, keeping the network secure and the data accurate."). So far, they have 3670 "clients", out of which 67% are "hosting", i.e. cloud platforms, with the following breakdown: Amazon 31%, Hetzner 17%, others 52%. Geographically, 32% of clients are in the US
- Solana has so far only 1022 validators and 683 RPC nodes (https://solanabeach.io/), which are mostly Solana's officially maintained nodes
- Avalanche advertises to have "thousands of nodes" but has only 1023 active delegators (https://avascan.info/staking/validators)
- Fantom currently has only 47 active validators (https://ftmscan.com/validators#) and recently partnered with StrongBlock to get more nodes...
- Binance Smart Chain currently has only 21 active validators (https://bscscan.com/validators)
- Tezos has totally 4794 nodes, out of which 371 public nodes (https://tzkt.io/network). 30% of the nodes are hosted by AWS and 25% in the US
- Elrond has currently 279 active validators (https://devnet-explorer.elrond.com/statistics?page=5)
- Polkadot has currently 652 validators (https://polkastats.io/)
- Cardano has 2855 "active pools" (https://pooltool.io/)
What can we learn from these figures?
1) The first and second generation blockchains like Bitcoin, Ethereum and Tezos are the most decentralized ones with more than 10k nodes for Bitcoin
2) The latest blockchains do not have many nodes yet (from 1k for Avalanche to 21 active validators for the BSC...) and work to develop their networks
3) Amazon Web Services (AWS) is the hosting leader with a market share around 30% at blockchains like Ethereum & Tezos, and 25% on all blockchains
The last point is a very important one. Totally, the centralized cloud service providers host around 60% of the nodes. Therefore, the decentralization level does not depend only on the number of nodes, but also on who hosts the nodes. What will happen if AWS suddenly decides to turn off the light?
The main blockchains should urge private users to set up nodes independently from the big cloud providers. It is the only way to be really decentralized.
Please feel free to let me know your thoughts or suggestions - e.g., regarding which blockchain is not mostly hosted by AWS... I will be very interested.