TL;DR: Layer 1 blockchains form the foundational ledger and consensus layer of a blockchain network. They store transactions, enforce security, and define the protocol rules, but must balance decentralization, security, and performance—a trade‑off known as the blockchain trilemma.
Overview of Layer 1#
A Layer 1 blockchain is the base protocol that maintains a decentralized ledger of transactions. It defines how blocks are created, linked, and validated by network participants (nodes). The core responsibilities include:
- Recording immutable transaction data.
- Enforcing consensus rules that determine which blocks are added.
- Providing security guarantees through cryptographic mechanisms.
The architecture of a Layer 1 chain is often described in four “layers” of abstraction. The RU canonical adds a concise definition of each layer:
| Layer | Role |
|---|---|
| L0 | Peer‑to‑peer network infrastructure for data exchange. |
| L1 | Base ledger that stores transactions and runs consensus. |
| L2 | Scalability solutions such as roll‑ups, plasma, or sidechains. |
| L3 | Application layer offering user‑friendly interfaces and dApps. |
Core Components of a Layer 1 Chain#
Building Blocks
Blocks are created by participants (miners in Proof‑of‑Work or validators in Proof‑of‑Stake). Each block contains a batch of transactions and a reference to the previous block, forming an immutable chain.
Transactions
Once a transaction is included in a block and the block is finalized, the record becomes permanent and cannot be altered or reversed. This immutability underpins trust in the system.
Consensus Mechanism
Consensus algorithms ensure that only valid blocks are added and that the network remains secure.
- Proof of Work (PoW) – Participants solve computational puzzles; the first to find a solution adds the block and receives a reward.
- Proof of Stake (PoS) – Validators lock up a stake of the native token; a validator is randomly selected to propose the next block and earns transaction fees.
TON as a Layer 1 Example#
The Open Network (TON) implements a PoS‑based Layer 1 with several distinguishing features:
- Integrated PoS Consensus – Provides security while minimizing energy use, enabling high throughput.
- Sharding – The network is divided into multiple shards that process transactions in parallel, increasing scalability.
- Security Model – Combines cryptographic encryption with decentralized consensus to protect against attacks.
These design choices help TON address the blockchain trilemma by improving scalability without sacrificing security or decentralization.
How Layer 1 Differs from L0, L2, and L3#
- L0 (Network Layer) – Supplies the underlying P2P communication protocols but does not store transaction data.
- L1 (Base Layer) – Stores the transaction ledger, runs consensus, and provides security; scalability is limited compared to higher layers.
- L2 (Scaling Layer) – Adds scalability via roll‑ups, sidechains, or plasma, offering faster, cheaper transactions at some security trade‑off.
- L3 (Application Layer) – Hosts user‑focused applications and interfaces, delivering richer UX while relying on lower layers for security and data integrity.