Layer 1 refers to the base blockchain protocol, the foundational network that provides security, consensus, and settlement finality. Bitcoin and Ethereum are Layer 1 networks. All transactions finally settle on the Layer 1, which is the source of truth. The security properties of Layer 1 come from its consensus mechanism and the economic value securing it.
Ethereum's Layer 1 is secured by hundreds of billions of dollars in staked ETH, attacking it would require acquiring a majority of that stake, which is economically impractical. The trade-off is scalability. Ethereum Layer 1 processes roughly 15 transactions per second. Bitcoin handles about 7.
These constraints exist because every validator must process every transaction to maintain decentralization. Increasing throughput on Layer 1 requires trade-offs: either larger blocks that fewer nodes can process, or faster consensus that increases centralization. This trilemma, security, decentralization, scalability, is why Layer 2 solutions emerged.
Rather than changing Layer 1 properties and compromising its security, faster layers are built on top that inherit Layer 1 security for final settlement.
Interactive Visualizer
Layer 1 Blockchain Security
Explore how base blockchain protocols maintain security through consensus mechanisms
Ethereum Layer 1
Network Security
Network is secure. Attack would require massive resources.
Consensus Mechanism
Key Insight: Layer 1 networks are the foundational source of truth. Their security comes from the economic cost of attacking them - requiring control of majority stake or mining power worth billions of dollars.