Ethereum Virtual Machine (EVM) and How It Executes Smart Contracts

The Ethereum blockchain has become a revolutionary platform for decentralized applications and smart contracts. At the heart of Ethereum lies the Ethereum Virtual Machine (EVM), which serves as the runtime environment for smart contracts. The EVM is a Turing complete virtual machine that enables the deployment and execution of smart contracts on the Ethereum network.

The EVM is like a global decentralized computer containing millions of executable objects, each with its own permanent data store. It provides a sandboxed runtime environment where smart contracts are executed deterministically and can access resources like bandwidth, memory, and processing power.

Smart contracts are immutable computer programs that run on the EVM according to preset conditions agreed upon by the transacting parties. They are programmed to autonomously execute tasks when the conditions are met. The code and data of smart contracts are stored on the blockchain and distributed across Ethereum nodes.

How Does the EVM Execute Smart Contracts?

When a smart contract is deployed on Ethereum, it is uploaded onto the blockchain and assigned a unique address. Users can then execute the smart contract by submitting a transaction and sending a message call to its address.

The transaction activates the smart contract code, which is then executed by the network of nodes on the EVM. Essentially, the EVM can be viewed as a large decentralized computer containing millions of objects called “accounts”. There are two types of accounts:

Externally Owned Accounts (EOAs)

These accounts are controlled by users through private keys and contain ether that is used to pay for transaction fees on the network.

Contract Accounts

These accounts are controlled by contract code and contain the smart contract's data.

When a user initiates a transaction to execute a smart contract function, the transaction is broadcast to the network and collected by miners. The transaction contains information like the recipient address, sender address, amount of ether to transfer, and most importantly, the data payload that encodes the function to call in the smart contract.

Miners then validate the transaction against a set of rules, and if valid, execute the smart contract function against the EVM. The EVM compiles the smart contract bytecode, enabling the code to be executed. It also provides the smart contract access to the data payload and information about the originating address and available funds.

The miners compute the result of the execution, as well as the amount of gas required, and stores the output and new state of the smart contract onto the blockchain. The updated state includes any changes made by the smart contract function, such as the transfer of funds.

Finally, the miner collects the execution fee based on the amount of gas used and includes it as part of the block reward. The execution of the smart contract function is now complete.

The deterministic nature of the EVM ensures that if the same function is executed on multiple nodes, they will all compute the same output and new state. This allows the network to reach consensus on the execution to update the blockchain.

Data Storage in the EVM

The EVM provides two types of storage for smart contracts - memory and storage. Understanding the difference between the two is important for optimizing smart contracts.

Memory

This is temporary and cleared between external function calls. Memory is volatile and resets after computation ends. It is faster to access but more expensive to use.

Storage

This is the permanent data storage of smart contracts. It is written to the blockchain. Storage is persistent and persists between function calls. It is slower to access but cheaper to use.

Well designed smart contracts efficiently use memory and storage to optimize computation and reduce costs. For example, simple variables and counters that do not need persistence can be stored in memory while data that needs to persist, like a user's balance, can be stored in a contract's storage.

Gas and Fees in the EVM

The concept of gas is crucial in the EVM to incentivize efficient computation and prevent infinite loops or other computational wastage.

When a transaction is executed, gas refers to the fee required to perform the computation. The gas cost of a transaction is the total amount of gas used multiplied by the gas price (in Ether). The gas mechanism ensures that complex computations that require more computational resources cost more, while simple computations have lower fees.

The gas cost is deducted from the user's account that initiated the transaction. The miner that executes the transaction and computes the result is awarded the gas cost as a fee. This incentivizes miners to include transactions with higher gas fees.

The deterministic nature of the EVM ensures that miners will arrive at the same gas cost for a transaction. Gas also prevents bugs or infinite loops in a smart contract from exhausting the network's computational resources. If a transaction runs out of gas during execution, any state changes are reverted, but the user still has to pay for the gas used up until that point.

The concept of gas makes the EVM a practical and economically sustainable transaction processing and smart contract execution engine.

Innovative Perspective: The Future of DecentralizedComputation

The Ethereum Virtual Machine represents one of the most significant innovations in blockchain technology. As the world becomes more digitally connected, decentralized systems like Ethereum will power greater automation, transparency and efficiency across industries through smart contracts. The deterministic and Turing complete nature of the EVM provides the reliability and computational completeness required for such applications.

Looking ahead, the EVM is poised to drive the web 3.0 revolution by serving as the trust layer for decentralized finance (DeFi), non-fungible tokens (NFTs), decentralized autonomous organizations (DAOs), and the metaverse. As more assets become tokenized on blockchain, the need for customizable and transparent rulesets will grow, and the EVM will be at the center of it all.

Beyond finance, the EVM could even be used for decentralized voting, transparent supply chains, identity management and disintermediating industries like insurance. The most profound impacts may be ones we can't even conceive today. Such is the nature of exponential technological change.

How Can Smart Contracts Scale While Retaining Decentralization?

For smart contracts and the EVM to realize their full potential, blockchain scalability remains an active area of research. Current scaling solutions include:

  • Sharding - Sharding partitions the network into multiple portions called shards each with its own transaction history and state. This allows parallel transaction processing and eases the storage and computational load on individual nodes.
  • Plasma - Plasma utilizes "child" blockchains anchored to the "parent" Ethereum blockchain to enable faster and cheaper transactions while benefiting from Ethereum's underlying security.
  • State Channels - State channels shift computations and transactions off-chain for faster throughput while storing the final state on-chain. They enhance scalability and reduce costs for interactions between recurring participants.
  • Layer 2 Solutions - Layer 2 solutions like Optimistic Rollups and ZK-Rollups bundle transactions off-chain before sending the aggregated data on-chain. This compresses the data and reduces fees.

The core challenges are ensuring these solutions preserve decentralization, security and transparency while enhancing scalability. Vitalik Buterin's vision of Ethereum as a "world computer" hinges on the ecosystem's ability to scale efficiently. With research ongoing, the future looks promising for Ethereum to deliver on its vast potential.

What Does Web 3.0 Mean for the Future of the Internet?

Web 3.0 represents an evolution of the internet toward decentralization, openness and enhanced user control. Some of its key aspects include:

  • Decentralization - Instead of a few centralized parties controlling networks, power is distributed among users through blockchain and peer-to-peer technologies. This reduces monopolistic intermediaries.
  • Ownership - Users have ownership of their own data and digital assets, rather than having them siloed by tech giants. Personal data sovereignty is restored through self-custody.
  • Transparency - Decentralized platforms like Ethereum enable transparency in transactions, agreements and value exchange, due to their public blockchains. Corruption and opacity are reduced.
  • Trustlessness - Central intermediaries are no longer the arbiters of trust. Trustlessness is achieved mathematically through cryptographic consensus and economic incentives. Censorship resistance is enhanced.
  • Open Collaboration - Open source protocols and autonomous organizations like DAOs enable collaboration at scale through incentives alignment, rather than centralized closed models. This unlocks network effects.

While still in its infancy, Web 3.0 represents an important shift in how the internet operates and creates value. Vitalik Buterin refers to it as the "internet of value". Its success depends on mainstream adoption, which will be driven by compelling decentralized applications that put users first. The future looks bright as the technology matures.

Conclusion

The Ethereum Virtual Machine is a game changer for enabling decentralized computing on a global scale. By executing smart contracts in a secure, deterministic manner, the EVM allows customizable and transparent business logic to run on blockchain. This opens up endless possibilities for decentralized applications in finance, governance, identity and beyond that can reduce corruption and monopolistic rent-seeking.

For the EVM and Web 3.0 vision to succeed, blockchain scalability and mainstream adoption remain key challenges. However, with some of the brightest minds in computer science and cryptography working on these issues, the future looks promising. The next decade may witness blockchain and smart contracts transforming industries in ways we cannot yet conceive.

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