State Tries

World State Trie

The World State Trie (WST), also called the State Trie or Global State Trie, is a critical data structure that represents the current state of all accounts on the Ethereum network.

• The trie is persisted to disk.

• All of the values are RLP-serialized accounts.

The figure below shows an example of world state trie with detailed node structure.

World State Trie Example

---

Account Storage Trie

The Account Storage Trie is a data structure used to store the persistent data of a smart contract. It is a Merkle Patricia Trie, like the World State Trie, and it maps storage keys to storage values for a specific contract account.

More details:

• Each contract account on Ethereum has its own Account Storage Trie, which stores the contract's persistent state variables.

• The storage trie is specific to a single contract and is separate from the World State Trie, which stores the global state of all accounts.

• The root hash of the Account Storage Trie is stored in the storageRoot field of the contract's account state (in the World State Trie).

Account storage trie example.

---

Transaction Trie

In the context of Ethereum, the Transaction Trie is a data structure used to store and organize all the transactions included in a specific block.

• Each block contains a Transaction Trie that holds all the transactions in that block.

• The transactions are indexed by their position in the block and are RLP-encoded.

• The root hash of this trie is stored in the block header (transactionsRoot field).

Transaction trie example.

---

Transaction Receipt Trie

The Transaction Receipt Trie records the receipts (outcomes) of transactions.

• A receipt is the result of a transaction that was executed successfully.

• Each receipt includes:

  • The transaction hash

  • Block number

  • Amount of gas used

  • Contract address (if a new contract was created)

  • Other execution metadata

• Like the Transaction Trie, this is a Merkle Patricia Trie whose root hash is stored in the block header (receiptsRoot field).

Transaction receipt trie example.