  WebAssemly is an emerging runtime for Web applications and has been supported
in almost all browsers. Recently, WebAssembly is further regarded to be a the
next-generation environment for blockchain applications, and has been adopted
by Ethereum, namely eWASM, to replace the state-of-the-art EVM. However,
whether and how well current eWASM outperforms EVM on blockchain clients is
still unknown. This paper conducts the first measurement study, to measure the
performance on WASM VM and EVM for executing smart contracts on blockchain. To
our surprise, the current WASM VM does not perform in expected performance. The
overhead introduced by WASM is really non-trivial. Our results highlight the
challenges when deploying WASM in practice, and provide insightful implications
for improvement space.
