Knowledge base
6 mins
What is WebAssembly (WASM)?

In the constantly evolving landscape of web development, a groundbreaking technology known as WebAssembly (WASM) plays an important role.


Originating as a collaborative effort among major browser vendors, WASM is an open standard that enhances web applications' performance and capabilities. It's a low-level, assembly-like language with a compact binary format designed to run at near-native speeds on the web. This technology has not only reshaped the boundaries of web applications but also holds significant implications for the world of cryptocurrency.

Technical Specifications of WASM

At its core, WASM is a binary instruction format for a stack-based virtual machine, making it a unique and efficient compilation target for various programming languages. Its design focuses on size and load-time efficiency, aiming to execute code at native speed by tapping into common hardware capabilities. WASM's integration with JavaScript is particularly noteworthy. It allows high-performance modules to run alongside traditional JavaScript, combining WebAssembly's power with JavaScript's flexibility. This synergy opens up a realm of possibilities for complex applications, including those in the cryptocurrency domain.

Security Aspects of WASM

WASM addresses security by providing a memory-safe, sandboxed execution environment. It's designed to operate within the existing security policies of web browsers, ensuring a secure execution of code. However, it's not without challenges. WASM has faced criticism for potentially easing the concealment of malware, including its use in unauthorized cryptocurrency mining. Despite these concerns, the technology continues to evolve, prioritizing robust security measures to mitigate such risks.

WebAssembly System Interface (WASI)

An intriguing aspect of WASM is the WebAssembly System Interface (WASI), which extends its capabilities beyond the web. WASI offers a simplified interface, allowing WASM to operate on various platforms, including server-side applications. This has profound implications for server-side computing and containerization, with some experts suggesting that WASI could have eliminated the need for solutions like Docker had it existed earlier. This versatility makes WASM an attractive option for developing decentralized applications in the cryptocurrency ecosystem.

Implementation and Adoption

WASM's implementation and adoption are testaments to its potential. It's supported by all major web browsers and has gained significant traction among developers. Its role in client and server applications is expanding, with an increasing number of use cases in various domains, including cryptocurrency. The technology is not just a tool for high-performance web applications but is also becoming a staple in the toolkit for developing sophisticated blockchain and cryptocurrency solutions.

Moreover, WebAssembly (WASM) is increasingly being recognized for its transformative role in blockchain virtual machines (VMs), offering several key advantages that are reshaping how smart contracts and decentralized applications (DApps) are developed and executed in the blockchain domain.

Key Advantages of WASM in Blockchain VMs

Performance Efficiency: WASM is designed as low-level bytecode, capable of quick and effective execution across various systems. This performance efficiency makes it particularly suitable for blockchain environments where rapid and effective execution is essential. The ability to execute code swiftly in blockchain VMs is critical for maintaining high transaction throughput and complex computations, a hallmark of blockchain applications.

**Language Flexibility and Development Ecosystem: **WASM supports a wide array of programming languages, including Rust, C/C++, C#, and others. This flexibility allows blockchain developers to write smart contracts in languages they are comfortable with, broadening the pool of potential developers who can contribute to blockchain projects. For instance, Rust-based frameworks like ink! compile to WASM, offering type and memory safety, beneficial for blockchain development. Additionally, some tools can compile other languages like Solidity to WASM, further expanding the language options for blockchain development.

Security Features: WASM's design incorporates features such as sandboxing and memory isolation, providing a robust defense against malicious programs. These security measures are critical in the blockchain context, where security and trust are paramount. The secure execution of smart contracts and DApps is essential to maintain the integrity and reliability of blockchain networks.

Portability Across Platforms: WASM code can be executed on any platform that supports it, including web browsers, servers, and even embedded devices. This portability means that code written for blockchain VMs can be more easily adapted and executed across different environments, enhancing the versatility and reach of blockchain applications.

Application in Blockchain VMs: Case Studies

Aleph Zero: Aleph Zero's smart contract pallet utilizes ink!, a Rust-based language that compiles to WASM, offering an open ecosystem for developers. This approach capitalizes on Rust's features like lack of runtime overhead and inherent security properties, making it an ideal choice for smart contract development in a blockchain context.

MultiversX: The MultiversX WASM VM is an example of a fast and secure virtual machine built specifically for executing smart contracts. It emphasizes statelessness in its design, where smart contracts don't directly write to the blockchain or storage during execution. This approach simplifies the execution process and enhances security. The VM uses Wasmer as an execution engine, allowing smart contracts to run at near-native speed. It also supports asynchronous calls between contracts, even across different shards, simplifying the development process for complex blockchain applications.

Cosmos and Polkadot: In Cosmos, WASM is used through CosmWASM, which allows for the development of smart contracts in multiple programming languages and enhances the performance and security of these contracts. Polkadot also utilizes WASM in its blockchain framework, Substrate, to enable flexible and efficient smart contract execution and blockchain development. WASM's integration in both these platforms significantly contributes to their versatility and capability in handling complex blockchain applications.

In summary, WebAssembly's integration into blockchain VMs is proving to be a game-changer. Its performance efficiency, security features, and support for multiple programming languages are enabling the development of faster, more secure, and versatile decentralized applications and smart contracts. This integration is paving the way for broader adoption and more sophisticated applications within the blockchain ecosystem.


In conclusion, WebAssembly represents a significant leap forward in web development, offering unparalleled efficiency, security, and flexibility. Its implications for the cryptocurrency world are particularly profound, providing a robust platform for developing complex, high-performance applications. As WASM continues to grow and evolve, it's set to play a central role in shaping the future of both web development and digital currency.