Verkle trees appear to be a crucial component of Ethereum's planned scaling enhancements. They serve the same purpose as Merkle trees in that you may load a huge amount of data into a Verkle tree and generate a brief proof ("witness") of any single piece, or group of pieces, of that data that can be confirmed by someone who possesses the tree's root.
The primary advantage of Verkle trees is that they are substantially more efficient in terms of proof size, enhancing the scalability of the Ethereum network. But what are these Verkle trees, and how are they different from Merkle roots? This article seeks to clarify all of that.
What Are Verkle Trees
Verkle Trees are an improved form of Merkle Trees that employ a new hash function. A Verkle tree, like a Merkle tree, is used in a blockchain to give a digest (footprint) of transactions. They are built in the same way as Merkle Trees but with vector commitments instead of cryptographic hash functions. A parent node in a Merkle tree is the hash of its children. A parent node in a Verkle Tree is the vector commitment of its children.
As a result, rather than proving each hash in the tree, the Verkle tree may be validated with a single proof. In addition, verkle trees will require less proof to prove that a piece of state is included in the chain.
These smaller proofs will allow stateless clients, i.e., nodes that do not maintain state, to propagate the network quicker, consuming less memory and less disk and I/O resources.
How Do Verkle Trees Work?
Using a Verkle tree, a proof for a tree with a billion data points will require less than 150 bytes. Verkle trees employ a proving technique known as Polynomial Commitments, which relies on polynomial functions to explain facts.
Each node has one of three properties: empty, a leaf node with a key and value, or an intermediate node with a fixed number of children, referred to as the tree's "width." A value's position in the tree is determined by its key.
A vector commitment scheme is a hash function that hashes a list. However, vector commitments have the unique characteristic that for a commitment and a value, a short proof that is the commitment to some list where the value at the i'th place is a given value may be constructed. This brief proof replaces the function of the sister nodes in a Merkle Patricia proof with a Verkle proof, providing the verifier assurance that a child node is indeed the child at the specified location of its parent node.
In practice, we utilize a primitive called a polynomial commitment, which is even more sophisticated than a vector commitment. Polynomial commitments allow you to hash a polynomial and create a proof for its assessment at any point. If we agree on standardized coordinates, polynomial commitments can be used as vector commitments.
What Are Its Features And Importance in Blockchain?
Verkle trees are well-known for their effective size-proofing properties. This is because Verkle trees can efficiently store data in a compact and structured manner, making them valuable for many applications. Verkle trees can assist in reducing proof size, which reduces the bandwidth required to verify the evidence. The proof length, which is often logarithmic in state size, influences network communication.
But what exactly is a Verkle proof? A Verkle proof is evidence of a significant quantity of data saved, which anybody with access to the tree's root may verify. Instead of showing all "sister nodes" at every level in Verkle trees, the prover must provide a single proof proving all parent-child relationships between all commitments along the pathways from each leaf node to the root.
Verkle trees can increase the efficiency of key management in negotiated protocols and public key directories.
Verkle trees can be employed in cryptocurrencies such as Bitcoin because they can swiftly verify deals and assist in maintaining track of them. In addition, verkle trees, a data structure that may be used to secure file systems and encrypt online applications, can be used to secure information.
How Does It Differ From Merkle Trees?
There are several distinctions between the two types of trees, notably in establishing Merkle and Verkle proofs. A Merkle tree's whole collection of sister nodes, including Merkle Patricia trees, provides proof of value. The evidence must contain all nodes in the tree that share a parent node with the node you're trying to verify.
In a Verkle tree, on the other hand, you need to provide the route plus a small bit extra as proof—you don't even need to add sister nodes. The primary idea behind the Verkle tree is that a Merkle tree can be built by substituting vector commitments for cryptographic hash functions.
A Verkle tree performs the same function as a Merkle tree. The key difference is that they are substantially more effective in terms of size in bytes.
Merkle proofs are easy to update, partly because of their tree-like structure, but Polynomial Commitments in Verkle trees need a full modification of the whole curve, which would be difficult to compute witnesses for.
Ethereum upgrades are aimed at achieving scalability; hence, further post-merge Ethereum upgrades will see the introduction of Verkle trees, which allow for substantially smaller proof sizes than Merkle proofs, consuming less data space on the blockchain and making transactions faster.
Hence, instead of providing all "sister nodes" at each level as typical with merkle trees, the prover has to submit a single proof demonstrating all parent-child links between all commitments along the pathways from each leaf node to the root. Compared to perfect Merkle trees, this allows proof sizes to be approximately reduced by a factor of 6-8.