Deepening Understanding of EIP-4844: The Key Breakthrough for Ethereum Layer 2 Scalability

Before the Dencun upgrade, Ethereum’s Layer 2 networks faced a fundamental dilemma. The solution to this dilemma is the highly anticipated EIP-4844 proposal. But before we understand the value of EIP-4844, we need to clarify what Layer 1 and Layer 2 are, and why existing L2 networks are caught in a cost swamp.

Layer 1 and Layer 2: Two Modes of Blockchain Operation

What is an independent Layer 1?

Layer 1 (L1) refers to a fully independent blockchain network. These networks do not rely on any external systems and possess all the capabilities needed for normal blockchain operation.

Common L1 projects include:

• Bitcoin: the earliest decentralized ledger
• Ethereum: smart contract platform
• Solana: high-performance blockchain
• Avalanche: multi-chain ecosystem

The shared characteristic of these networks is: besides running independently and fully, they can also serve as infrastructure for other blockchains. These Layer 1-based networks are called Layer 2 (L2).

Layer 2 Design Logic: Function Separation

Layer 2 is built on top of L1. L2 does not need to perform all blockchain functions but adopts a division of labor: L2 handles computation and transaction execution, while L1 is responsible for security and data storage.

To use a computer analogy:

• L1 is like a hard drive, permanently storing L2’s transaction history
• L2 is like a processor, quickly executing various computations and transactions

Users can transact directly on L2 or verify everything by querying transaction records on L1. This architecture gives L2 security close to L1 while enabling much faster processing speeds.

Data Availability: The Lifeblood of L2

Why is L1 so important to L2? The key lies in data availability.

L2 networks cannot maintain a full node network to store their own history, so they must have a place to record all transactions. This place is L1. Anyone can view the data stored on L1 to verify whether the L2 network is functioning correctly.

L1 acts as the data availability layer for L2, ensuring transparency and verifiability. Without it, L2 cannot gain sufficient trust.

Two Validation Methods for Rollup

Currently, the main L2 solutions are Optimistic Rollup and ZK Rollup. Their difference lies in how they prove that transactions have been correctly executed.

Optimistic Rollup: Believe First, Dispute Later

The logic of this scheme is simple:

1. L2 executes transactions
2. Publishes transaction results to L1
3. Allows anyone to raise disputes within a certain period

If someone finds an error (e.g., Arbitrum mishandling a transfer), they can raise a dispute and receive a reward. This mechanism is akin to “trust first, verify later.”

ZK Rollup: Provide Proof, Verify Directly

This scheme requires pre-proving:

1. Transactions are executed in a special EVM environment
2. Generate a mathematical proof of correct execution
3. Publish both transactions and proof to L1
4. Anyone can verify the validity of the proof

This approach is more like “here is the result, here is the proof.” Verifying the proof is much cheaper than re-running all transactions.

Before EIP-4844: The Crux of Calldata

Prior to the EIP-4844 proposal, L2 networks had a clever way to store data: using the transaction’s calldata field.

Calldata is a special space in blockchain transactions used to record user instructions. L2 networks thought of a smart method: embed their transactions, execution proofs, and results into calldata and write it into L1.

This method is indeed clever because it allows L2 to leverage Ethereum’s security and decentralization to ensure their transaction records cannot be tampered with.

But problems followed: all users’ transactions, whether from L1 or L2, compete in the same fee market.

When NFT minting on Ethereum becomes hot and gas prices soar, the cost for L2 to publish data also rises, ultimately increasing transaction fees on L2. Conversely, when L2 needs to publish大量 data, L1 users are also affected. It’s like two lanes of traffic interfering with each other.

EIP-4844: Creating a Dedicated Channel for L2

Faced with this dilemma, the Ethereum community designed an elegant solution: create an independent space for L2.

The core idea of EIP-4844 is “let L2 do its own thing without disturbing Ethereum users.” To achieve this, it introduces a new transaction type that allows L2 to publish data into a brand-new area: blobspace.

Blobspace is an added part of Ethereum blocks, dedicated to carrying L2 data. More importantly, EIP-4844 creates a separate fee market for blobspace. This means:

• L1 users’ transaction fees are no longer affected by L2 data publishing
• The costs for L2 networks are no longer tied to Ethereum’s gas fluctuations
• Both sides operate independently without interference

According to developer forecasts, this upgrade is expected to reduce L2 transaction gas costs by about 10 times. For users, this means much cheaper transactions on L2; for L2 projects, lower operational costs; for the entire Ethereum ecosystem, increased competitiveness.

The True Significance of the Dencun Upgrade

From a technical perspective, the Dencun upgrade mainly changes how L2 writes and submits transaction sets on Ethereum. Users do not need to understand these underlying details.

From a user experience perspective, the changes are straightforward:

• Significantly lower transaction fees on L2
• Reduced gas pressure on L1 during high activity on L2

Although EIP-4844 is a technical proposal, it addresses the most fundamental problem faced by the Layer 2 ecosystem—the balance between cost and efficiency. This is precisely why it is regarded as a key turning point for Ethereum and L2 development.