Introduction

There are four types of state tries:

• World State Trie

• Transaction Trie

• Transaction Receipt Trie

• Account Storage Trie

Each state trie is constructed using a Merkle Patricia Trie (MPT) .

Each block stores three central state tries:

• World State Trie

• Transaction Trie

• Receipt Trie

The Account Storage Trie (also known as the account storage contents trie) constructs the leaf nodes in the world state trie.

Block Structure

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Why Use Merkle Patricia Trie?

The Merkle Patricia Trie data structure is used for the following reasons:

• Efficient Lookups: Tries allow for efficient key-value lookups, insertions, and deletions with O(log(n)) performance.

• Cryptographic Verification: The Merkle tree structure enables cryptographic proofs of the data's integrity. Each node in the trie is hashed, and the root hash (stored in the block header) serves as a fingerprint of the entire state.

• Incremental Updates: Only the parts of the trie that are modified need to be updated, making it efficient for frequent state changes.