The IOTA Qubic team have been reviewing the options for resource tests within the Qubic Protocol.
This part of the project develops Tangle based Quorum-Based Computations, establishing a platform which is global and decentralised and enables new economic models, Industry 4.0 and Web 3.0.
In basic terms, the Qubic Protocol is a means for using distributed machines to run a computer program, such as for executing smart contract type transactions. These transactions do not require centralised trust, with consensus being reached from the machines within the quorum. The Protocol contains two stages, the resource test phase and the Qubic processing phase, with the total of these stages being referred to as an epoch.
The resource test phase involves allocating to each machine within the ‘assembly’ the proportions of rewards that they will receive once the task or transaction is complete. There are a number of ways in which these allocations can take place, and it is these options that are being reviewed.
Proof of Work (PoW) is a simple method and involves the machines carrying out a test, such as completing puzzles within a set amount of time. The output of the test drives the allocation. However, PoW itself has no productive output and is costly and time-consuming to run.
Proof of Stake (PoS) is an alternative option. This involves reviewing the output of previous tasks or transactions to determine each machine’s stake. If a machine does not participate in a particular epoch, their stake is lost and another machine may take their place. In these instances, the PoS may be combined with an additional PoW.
The other options also being reviewed include Proof of Ownership, Proof of Biometrics, Proof of Sale, Proof of Identification or any other Proof of X system (PoX). A resource test will always be required within the Qubic Protocol, both as an anti-Sybil measure but also to separate out the individual epochs and check the participation of all of the relevant machines ensuring they are rewarded fairly.
The Qubic math paper and initial code will be released in the near future, along with a full roadmap for the development project. There is an early view of the Qubic roadmap available now.
You can read more on the official IOTA blog.