Oasis Network is a permissionless, blockchain-based cloud computing platform that aims to improve upon the scalability and privacy of its peers through novel architecture. In some regards, Oasis functions similarly to existing smart contract platforms: a modified version of Ethereum’s gas model is used to compensate smart contract execution, nodes must stake tokens in order to operate and receive block rewards, and consensus is reached using a Proof-of-Stake mechanism. However, Oasis differentiates itself through its incorporation the Nimble and Ekiden protocols, which utilize node ‘committees’ and trusted execution environments (TEEs), respectively.
The Nimble blockchain architecture utilized by the Oasis Network offers an alternative to the ‘sharding’ approach to improving blockchain scalability. Rather than establishing multiple sub-chains, Nimble delegates tasks to a series of specialized ‘committees,’ allowing many functions to be performed in parallel, thus enhancing network throughput. Committee members are compensated with ‘gas’ fees and block rewards, though the size of such payments is currently unknown. A ‘Committee Scheduler’ algorithm automatically and randomly selects committees of nodes meeting predefined conditions. Those wishing to act as committee nodes must stake a portion of their holdings, which may be forfeited for absenteeism, production of conflicting bundles, invalid computation or proofs, improper storage or merging and misconduct during the consensus process. The five committees, and their respective functions, comprising the Nimble protocol are:
- Transaction Scheduler Committee: Nimble’s computation process begins with users submitting proposed transactions via gateways to the ‘Transaction Scheduler Committee,’ which then packages transactions together based on computation requirements. The Transaction Scheduler Committee then sends each bundle to the Compute Committee best suited to meet such requirements. The Transaction Scheduler committee is comprised of a ‘leader,’ who packages and assigns bundles to compute committees, and ‘verifiers,’ who confirm that “no two batches interfere with each other” before sending them to the compute committees. Leaders and verifiers are randomly designated by the Committee Scheduler.
- Compute Committees: In contrast to the singular Transaction Scheduler Committee, numerous ‘Compute Committees’— dynamically formed and of varying computational capabilities—exist within the Oasis Network. Once assigned a bundle of proposed transactions, individual members of a given Compute Committee are responsible for actually executing these transactions based on their underlying smart contracts. In contrast to platforms such as Ethereum, in which every node must execute every smart contract, Oasis’ Compute Committees are each assigned unique batches of contracts to execute, allowing their computation to occur in parallel, enhancing network throughput and, thus, scalability.
- Merge Committee: The Merge Committee acts as a compiler, hashing and packaging computed transactions received from all Compute Committees into blocks. These blocks are then sent to the Consensus Committee for validation. No additional analysis or consensus occurs during this phase.
- Storage Committee: The Storage Committee exists adjacent to both the Compute Committee and the Merge Committee, consistently interacting with both. Members of this committee store the results of partially executed smart contracts received from the Merge Committee; they record and communicate to the Compute Committee the states of these smart contracts as new, partial computations continue to be executed. Once finalized, the transaction is sent via a Compute Committee to the Merge Committee, as any other transaction would be.
- Consensus Committee: Upon receipt of transaction blocks from the Merge Committee, the Consensus Committee validates these transactions according to the Tendermint consensus protocol. Valid blocks containing final transaction states are then added to a canonical blockchain.
Oasis further distinguishes itself through its privacy-enhancing Ekiden protocol: a framework for the use of trusted execution environments by members of Compute Committees. In the Oasis Network, TEEs—essentially, isolated hardware devices providing secure enclaves for computation—may be employed by some Compute Committees to execute smart contracts off-chain, ultimately recording on the blockchain only a finalized transaction state and a cryptographic proof confirming proper contract execution. Thus, in separating computation from consensus, such a protocol theoretically shields sensitive smart contract data from exposure to the public blockchain and, thus, external observers. In doing so, it intends to attract to a permissionless blockchain otherwise incompatible projects in fields such as those involving private medical and financial data.
Oasis Labs is headed by CEO Dawn Song, a MacArthur Fellow, Professor of Computer Science at UC Berkeley, and reportedly the most cited scholar in computer security literature to date. Also contributing to the project is Ari Juels, a professor at Cornell Tech and collaborator on Chainlink’s recent Mixicles project. The remainder of the Oasis team is largely comprised of academic researchers from institutions including MIT, Stanford, and the University of Washington.
Oasis’ eponymous native cryptoasset (Ticker: OASIS) is used to pay gas fees for smart contract execution and block rewards. In July of 2018, Oasis held a private token sale, in which $45M worth of Oasis tokens were sold to investors including Andreesen Horowitz, Binance and Polychain Capital. While initial tokens were created using the Xevan algorithm, all subsequent tokens are generated through PoS block rewards.