Types of Blockchains
Blockchains are not one-size-fits-all. Different use cases require different levels of openness, speed, and control. The four main types vary based on who can participate and who can read the data.
Blockchain Types Comparison
┌─────────────────────────────────────────────────────────────────┐
│ PUBLIC PRIVATE CONSORTIUM HYBRID│
├─────────────────────────────────────────────────────────────────┤
│ Access │ Open │ Invite only │ Group │ Mixed │
│ Participants │ Anyone │ One org │ Multiple │ Both │
│ Speed │ Slow │ Fast │ Medium │ Varied│
│ Decentral. │ High │ Low │ Medium │ Varied│
│ Privacy │ Transparent │ Private │ Selective │ Mixed │
│ Consensus │ PoW / PoS │ Custom │ Vote / PBFT│ Mixed │
│ Examples │ Bitcoin, │ Hyperledger│ R3 Corda │ │
│ │ Ethereum │ Fabric │ Energy Web │ │
└─────────────────────────────────────────────────────────────────┘
Public Blockchains
Anyone can join, read, write, and participate in consensus. They are fully decentralized and transparent. Bitcoin and Ethereum are the most well-known public blockchains. The tradeoff is lower throughput since thousands of nodes must process every transaction.
Private Blockchains
A single organization controls who participates. They are faster and more efficient since fewer nodes need to agree, but they sacrifice decentralization. Useful for internal enterprise workflows where privacy and speed matter more than open access.
Consortium Blockchains
A group of organizations jointly operates the blockchain. Consensus is reached among the known participants. This model is common in banking (R3 Corda), supply chain (TradeLens), and energy sectors where trusted parties need shared infrastructure without a single point of control.
Hybrid Blockchains
Combine public and private elements. Some data is publicly verifiable while other data remains private. This allows organizations to prove integrity to the outside world while keeping sensitive business logic confidential.