What is an Ethereum Virtual Machine (EVM) and how does it work?

Ether (ETH), which is the second largest cryptocurrency by market capitalization, is popular among crypto investors due to its native ETH token. However, its native Solidity programming language and Ethereum Virtual Machine (EVM) are instrumental in the adulation it receives from the developer community. In fact, the Ethereum blockchain continues to attract decentralized application (DApp) developers due to its flexibility, the wide range of available developer tools, and the platform’s large user base.

Forming the core of the blockchain’s architecture, the EVM is the program that executes its application code or smart contracts, as they are called, providing a runtime environment for them that runs on the Ethereum network. In addition, the EVM is Turing-complete and can thus run any program coded in any programming language, thus allowing developers to easily create custom smart contracts and DApps for the burgeoning Web3 space.

In addition to these important functions, EVM has access to all nodes on the network, handles the execution of smart contracts and efficiently handles all transactions on the Ethereum blockchain, making it one of the most powerful virtual machines in existence today.

What is Ethereum Virtual Machine (EVM) and how does it work?

Conceived in 2013 by developer Vitalik Buterin, the Ethereum network owes its phenomenal success as the blockchain of choice for DApp developers to the Ethereum Virtual Machine (EVM), which was designed by Gavin Wood during his tenure at Ethereum. Written in C++ and using the LLVM Project compiler, EVM is a special state machine that runs continuously and whose immutable operations determine the state of each block in the Ethereum blockchain.

The EVM not only controls what nodes can or cannot do to the distributed ledger maintained by the Ethereum blockchain, but also defines the specific rules for changing state from block to block. The latter functionality is what enables the smart contract functionality that Ethereum is known for.

To understand what the Ethereum Virtual Machine does, one must look at each of the different functions it serves to ensure the smooth operation of the Ethereum network. For every input it receives, the EVM produces an output that is deterministic in nature and follows a mathematical function in the simplest sense.

Operating as a stack machine that pushes transient values ​​to and from a pushdown stack, the EVM has a depth of 1024 items, each of which is a 256-bit word. It also stores temporary memory in the form of a byte array that changes between two transactions on the Ethereum blockchain. Smart contract codes that have been compiled are executed by the EVM in the form of a collection of 140 standard opcodes, while other blockchain-specific stack operations are also executed by it.

Thus, the EVM has a machine state that is volatile in nature during the processing of any transaction and a global or world state that contains information about the different accounts stored on the Ethereum blockchain. All actions are controlled by the EVM code, which itself has gone through several iterations since the launch of the Ethereum network in 2015, leading to the existence of different implementations of the EVM currently in use.

In fact, the EVM is responsible for maintaining a level of abstraction between thousands of Ethereum nodes and the executing code, acting as a function that delivers consistent results without revealing many details to clients or nodes.

What is the purpose of the Ethereum Virtual Machine (EVM)?

The EVM reliably powered all applications running on the Ethereum network with no major downtime reported. For developers, the EVM acts as the general program that runs smaller executable programs that are known as smart contracts in Ethereum, while giving them the freedom to write these smart contracts in various programming languages ​​including Solidity, Vyper, Python and Yul, among them. others.

Because of this flexibility offered by the EVM, the Ethereum blockchain has spawned thousands of DApps in the decentralized finance (DeFi) and non-fungible token (NFT) fields. Each of these DApps and the smart contracts they are made of are converted into bytecode, which is entered into the EVM and distributed among all nodes on the Ethereum network. When a smart contract is deployed, the EVM is responsible for communicating with all nodes and effecting state changes when consensus has been reached.

It can be said that the EVM is embedded inside each Ethereum node to execute smart contracts using bytecode instead of the basic programming language, thus isolating the physical host computer from the machine code on which Ethereum runs.

Advantages of Ethereum Virtual Machine (EVM)

Because of the way the EVM works, developers can execute code without worrying about its impact on the rest of the network or the possibility of it playing with data or personal files hosted on any of the node computers.

Additionally, they can run complex smart contracts in different computing environments with distributed consensus. This ensures that the failure of a single node does not have any negative impact on the operation of the DApp or smart contract, as the EVM code remains the same across all nodes. Additionally, since account data is stored at a global level in the EVM, developers find it perfect to write custom smart contract code and create separate DApps that can access this global data set and produce reliable outputs.

The sanctity of the result is what makes the EVM, in particular, and the Ethereum blockchain in general well suited for the sustainable expansion of the DApps and smart contract Ethereum ecosystem. Add to this the library of standard codes available for developers to choose from, a growing number of EVM-compatible layer-2 blockchains and a large number of potential EVM use cases possible, and it’s easy to see why the EVM is the platform of choice. for Web3 development.

Disadvantages of Ethereum Virtual Machine (EVM)

Despite the many advantages offered by the EVM, there are certain disadvantages that must be considered by developers and entrepreneurs building on Ethereum. The most important of these are the high transaction fees or gas costs associated with running a smart contract on the Ethereum network.

Paid in ETH, these fees vary according to the complexity of the contract and the network congestion at the time of execution, making it imperative for developers and entrepreneurs to price their services accordingly. Furthermore, since Solidity is the most preferred language for coding on the EVM, it implies that developers must have adequate experience with it and possess some technical expertise to create effective smart contracts using it.

The latter is important because any additional computing requirement will lead to higher gas costs and ultimately prove detrimental to the success of the project. If developers choose to code using other languages, they must be careful to resolve any inherent repetitions in the code because the EVM will compile them anyway. While updating smart contracts is possible at a later stage, it comes with security risks associated with creating an intermediary smart contract that references the address of the original smart contract.

The future of EVMs

Despite the revolutionary changes brought about by the EVM to the blockchain ecosystem, this technology for reading and executing code is improved by a number of blockchain projects.

With cross-chain interoperability being the most important aspect for developers, many EVM-compatible blockchains have supported themselves, with most offering lower gas and faster transaction speeds than the Ethereum protocol. As a result, these blockchains can now interact with Ethereum users seamlessly and facilitate money transfers to their own networks using blockchain bridges.

However, with the Ethereum protocol successfully completing the Merger in September 2022, the next goal is to switch from EVM to Ethereum WebAssembly (eWASM). Designed to be highly modular and platform independent, eWASM is touted as the next game changer for the Ethereum protocol and could encourage other blockchains to use this runtime environment for smart contracts as well. However, whether eWASMs will replace the EVM as the most reliable mechanism for smart contracts is a question that only time will answer.