Blockchain scalability
The blockchain trilemma says that a network can have only two of three things: security, decentralization, and scale. Bitcoin chose security and decentralization. Solana chose scale. Ethereum moved scale to rollups. Quai's answer is to add chains, not weight: many small chains that the same proof-of-work miners secure together.
What the trilemma is
A blockchain is secure and decentralized when many independent people can run a node and check everything. A node is cheap when blocks are small and slow. That is why Bitcoin handles about seven transactions per second.
To get more transactions on one chain, the blocks must be bigger or faster. Then nodes need more bandwidth, storage, and computing power, fewer people can run one, and the network becomes less decentralized. That trade is the trilemma.
Four ways to scale, and what each one gives up
| Approach | Examples | What it gives up |
|---|---|---|
| Bigger or faster blocks on one chain | Bitcoin Cash, Solana | Decentralization. Nodes become costly to run. |
| Layer 2 | Lightning, Ethereum rollups | One shared network. Users and liquidity are split, with bridges and operators to trust. |
| Proof of stake with small validator sets | Many newer chains | Open entry. A known group of large holders produces the blocks. |
| More chains with shared proof of work | Quai | Nothing in the security model. Each chain stays small, and all share one set of miners. |
How Quai scales proof of work
Many chains, one set of miners
Quai runs a hierarchy of chains. Through merged mining, the same miners secure all of them at once, so a new chain adds capacity without a split in security.
No wait to pick a block
Quai's consensus, PoEM, measures the full weight of each block's hash. Nodes choose between two competing blocks at once, which is what makes many proof-of-work chains work together.
Blocks every 5 seconds
A Quai block arrives about every 5 seconds, against about 10 minutes on Bitcoin.
Smart contracts on the base layer
Quai runs the Ethereum Virtual Machine, so Solidity contracts and Ethereum tools work on a proof-of-work chain.
Small nodes
Each chain stays small, so a node does not need a data center. The design targets more than 50,000 transactions per second as chains are added.
Nothing wasted
Workshares pay near-miss mining attempts. Through SOAP, the same work also mines Bitcoin Cash, Litecoin, Dogecoin, and Ravencoin, and those rewards buy and burn QUAI.
Questions people ask
What is the blockchain trilemma?
It is the idea that a blockchain can have only two of three properties at once: security, decentralization, and scalability. A chain that raises its speed with bigger blocks makes nodes costly, and fewer people can run them.
Has anyone solved the blockchain trilemma?
Quai is built to. It does not make one chain heavier. It adds chains, and the same proof-of-work miners secure all of them through merged mining, so scale does not cost security or decentralization.
What is sharding?
Sharding splits a blockchain's work across several chains. The hard part is security: a split of the validators weakens each shard. Quai solves this with merged mining, where every miner works on every level of the hierarchy at once.
How many transactions per second can Quai handle?
The design targets more than 50,000 transactions per second as chains are added. Each chain produces a block about every 5 seconds.
Is layer 2 the same as scaling?
Layer 2 moves activity to separate networks. It lowers fees, but it splits users and adds bridges and operators. Quai scales the base layer itself.
Read next
Sources
This page gives information only. It is not financial advice. See the disclaimers.