Technical Architecture

How Ares Works

Participants

Aggregator

The aggregator obtains external request data through Scanner, and sends the request to the processor to process all Oracle requests. An aggregator is randomly selected through the VRF algorithm. It calls the processor to aggregate data from multiple data sources and submits it to the block, and broadcasts it to the Ares network through the block propagation protocol.

Challenger

The challenger verifies the integrity and validity of the data submitted by the aggregator, and submits fraudulent aggregator transactions and correct data to the Reputation Committee for rewards.

Reputation Committee

By motivating challengers and punishing malicious aggregators, the security of the Area network is ensured. The Reputation Committee is fully self-governing by the community, running for the Reputation Committee through token mortgage and reputation weighting. The internal arbitration of the Reputation Committee needs to vote through the FSP fraud security protocol, and only runs when there is a dispute on the chain.

Data consumer

Data consumers can be objects that need to obtain external data in smart contracts, parachains, and DAPPs. They can provide various credible and effective data for DEFI, market predicting, and gambling. Because Ares’s on-chain data has a certain data challenge period, data Consumers should obtain data on the chain according to certain safety regulations.

Node operator

The node operator, as a full node of the Ares network, verifies the data by comparing with the locally stored data to ensure the security of the Ares network and provide Oracle RPC service.

Detailed design

Ares Protocol is based on Substrate 2.0 and is used as a parallel chain/parallel thread to connect to the Polkadot ecosystem. The specific process is as follows:

Polkadot ecological parachain, through the integration of Ares oracle pallet, submit data requests; Scanner obtains external request data and submits it to the aggregator; Ares Chain randomly selects an aggregator through the VRF algorithm; The aggregator calls the processor to aggregate data from multiple data sources and submit it to the Ares blockchain; The verification node will verify the data of the aggregator and challenge; The Reputation Committee verifies the data submitted by the challenger and conducts arbitration.

How to solve decentralization?

Ares proposed two solutions to avoid the emergence of problem nodes as much as possible, namely distributed data sources and distributed oracles.

Distributed data source

Each node operator obtains data from multiple different data sources to reduce the impact of abnormal data sources on the results. Aggregate functions can aggregate multiple returned results into a single answer. There are many solutions to complete data aggregation, such as the weighted average after removing abnormal data.

Data sources may obtain data from each other, which may also lead to errors in aggregation results. We will continue to pay attention to such issues and report on the independence of data sources.

Distributed aggregator

The aggregator (i.e., miner) is mainly responsible for providing various types of data, and the challenger (i.e., validator) verifies and challenges the various data provided by the data provider and sends it to the parliament (arbitration institution). The Reputation Committee arbitrates the challenge presented by the data verifier, and if the verification passes, it rewards the challenger and punishes the aggregator.

Among all the aggregator miner nodes that provide data quotations, Ares Network uses a verifiable random function (VRF) to randomly select a group of aggregator nodes to compete to provide the most accurate market data. By introducing VRF into the system, the degree of dispersion of the system can be significantly improved.

Randomly select aggregator nodes through VRF to provide external data on the chain.

After the calculation of VRF, Ares can select the aggregator, and finally determine that a certain aggregator produces blocks at the current height, and verifies the aggregator through zero-knowledge proof. This part will be broadcasted at the same time as the block is produced and the ordinary verification node will verify after receiving the block. If it is within the allowable deviation range, the verification will pass.

Reputation committee governance

The BFT (Byzantine Fault-Tolerant) algorithm began to be studied in the 1980s to solve the so-called Byzantine Generals problem. The most famous BFT algorithm is PBFT, which is a consensus algorithm based on message passing. In a weakly synchronized network, the algorithm can reach consistency through three stages, and the complexity is O(n2). When an agreement cannot be reached, these stages will be repeated until the timeout.

The advantages of PBFT are fast convergence speed, resource saving, and theoretical security circle (in theory, no more than 1/3 of malicious nodes are allowed to exist, that is, the total number of nodes is 3k + 1, and when there are more than 2k + 1 normal nodes, The algorithm works normally).

Members of the council are selected from aggregators or token holders, and there is a mapping ratio between reputation value and token holdings. Ensure that members of the council will not be manipulated by currency holders. Every time an aggregator submits correct data, its reputation value will increase. A list of council members and a waiting queue will be maintained, and council members will be updated every month. The council can only approve or reject the fraud-proof submitted by challengers. Since the challenge is to pay a certain amount of GAS fees, the council does not need to work under normal circumstances. It only needs to handle the dispute when the verifier submits the fraud-proof, and can submit the fraud-proof to the council. If the committee verifies that the fraud fraud-proof, it will reward challengers and punish aggregators, and its reputation will decline.

When parliament members deal with challenger disputes, they need to use the BFT algorithm for quick confirmation. A security interval will be set here. If the aggregator puts the data on the chain, the verifier finds a data error during verification and issues it in the next block. It is broadcast before the block. At this time, the reward received by the challenger for winning is the highest. The reward will be distributed to members of the parliament. A small part of the reward will be distributed to the national treasury. When the data is wrong, it will be used to apply for compensation. Discussed in the governance module.

How to resolve disputes?

The security of the Ares network is guaranteed by a very strict POS with penalties. If a node operator is identified as an attacker, all Ares tokens pledged by him will be allocated to the reputation committee, challenger, and treasury.

Corresponding to different data markets, such as DEFI, in order to prevent malicious quotations, Ares has designed a challenge mechanism in which the challenger (any Ares full node) can object to the quotation. Initiating a challenge requires paying a small amount of ARES tokens and broadcasting them to the Reputation Committee. Suppose 2/3 of the nodes of the Reputation Committee are audited as malicious. In that case, he will be marked as a malicious node, the mortgaged token is frozen, and the node mortgaged token was transferred to the Reputation Committee, Challenger, and Treasury.

But in extreme cases, when data consumers suffer losses due to malicious nodes reporting data, they can initiate a proposal to the state treasury to apply for compensation, and then vote through the community, and after passing the state treasury to compensate the data consumers.