In this article, we discuss the decentralization, security and scalability tradeoffs among multiple technologies in the field of decentralized computing.
Vitalik Buterin introduced the blockchain scalability trilemma. Generally speaking, the trilemma says that simple blockchain architectures can only get two of the following three properties: decentralization, security and scalability.
Ethereum has been referred to as a "world computer", a global, decentralized, general-purpose, shared-state machine. However, Ethereum and all other general-purpose blockchains provide a very isolated and computationally limited execution environment. In particular, blockchains are unable to carry out expensive computational tasks (e.g. run a deep neural network), and interoperate with external systems (e.g. connect to the Internet, react to off-chain events and interact with other blockchains).
Nexus is a solution to both limitations and a challenge to the "blockchain as a world computer" paradigm. Nexus is a large-scale, general-purpose, Decentralized Cloud Computing Network. It enables blockchains to outsource computation and interoperate with external systems, like the Internet. It achieves this by introducing the first stateless, general-purpose, decentralized cloud computing platform powered by Multi-Party Computation (MPC) technology, allowing developers to program their own custom blockchain oracles.
By connecting blockchains to a programmable off-chain consensus engine, Nexus provides the missing piece of infrastructure needed to make blockchain applications interoperable with the outside world. From computational oracles, to machine learning oracles, to human identity oracles, to insurance oracles, to sports oracles, to gaming oracles, to cross-chain oracles, to zero-knowledge oracles, to reactive oracles, to market data oracles, to outbound oracles, to automation oracles, to randomness oracles, and more, developers can program and deploy arbitrary oracle applications on the Nexus Cloud and massively extend the computational and I/O capabilities of smart contracts.