Arbitrum is a layer 2 solution designed to improve the capabilities of Ethereum smart contracts — boosting their speed and scalability, while adding in additional privacy features to boot.

The platform is designed to allow developers to easily run unmodified Ethereum Virtual Machine (EVM) contracts and Ethereum transactions on a second layer, while still benefiting from Ethereum's excellent layer 1 security.

It’s built to address some of the shortcomings of current Ethereum-based smart contracts — such as poor efficiency and high execution costs — which have damaged the Ethereum user experience and frequently make transacting an expensive task.

Arbitrum uses a technique known as transaction rollups to record batches of submitted transactions on the Ethereum main chain, and execute them on a cheap, scalable layer 2 sidechain while leveraging Ethereum to ensure correct results. This process helps to offload most of the computational and storage burden Ethereum currently suffers from, while enabling new classes of powerful layer 2-based DApps.

New York-based development firm Offchain Labs is currently building the Arbitrum product, as well as an entire suite of scaling solutions. The initiative is spearheaded by Offchain Labs co-founders Ed Felten, Steven Goldfeder and Harry Kalodner. Ed is a professor, Steven received his Ph.D, and Harry is a Ph.D. candidate at Princeton University. All three are blockchain experts with a passion for making cryptocurrencies more capable.