Blockchain Basics & Architecture

The Architecture of Solana

Solana is fundamentally different from other blockchains like Ethereum or Bitcoin. Instead of relying on a global mempool where miners choose the highest-paying transactions, Solana uses several core innovations to achieve high throughput and low latency.

Proof of History (PoH)

The most critical innovation is Proof of History. Think of PoH as a cryptographic clock. Instead of nodes communicating back and forth to agree on when a transaction happened, PoH allows the network to embed historical timestamps directly into the ledger using a recursive SHA-256 hashing function.

Because all validators trust this clock, they can process transactions continuously without waiting for other nodes to confirm blocks.

The Account Model

On Ethereum, smart contracts are tightly coupled with their state (data). On Solana, programs are stateless.

• Programs (Executable Accounts): Store the compiled bytecode. They cannot store user data.
• Data Accounts: Store state. When you execute a program, you must pass in the specific data accounts you want it to read or modify.

This separation allows Solana to execute thousands of transactions in parallel. If Transaction A touches Account X, and Transaction B touches Account Y, they can be processed at the exact same time by the runtime (Sealevel).

Public Key Cryptography

Every user and account on Solana is identified by a Keypair:

• Public Key: Your wallet address (starts with a base58 string).
• Private Key: The secret you use to sign transactions and prove ownership.

Solana uses the Ed25519 elliptic curve for its cryptography.