# A Blockchain-Based Trust Model for Uploading Illegal Data Identification
## 3 Trust Model for Uploading Illegal Data Identification
### Scheme Architecture  
The trust model for uploading illegal data identification is shown in Figure 1. The trust model consists of the following two types of smart contracts: the smart contract of identification node pool (Smart Contract of Identification Node Pool, INPSC) and the smart contract of identification (Smart Contract of Identification, ISC). INPSC mainly has the following three responsibilities: NN registration, NN state transition, and IN selection. NN has the opportunity to be a member of INs only through the registration function and being \"Online\". In this trust model, the incentive mechanism of IBC is to provide credit and token incentives for INs. The more INs, the more reliable the model is and the higher the credibility. The process of a trust model for uploading illegal data identification is shown in Figure 1. Firstly, IBC generates INPSC and ISC. Before identification begins, the IBC is required to negotiate identification treaties with the IDBC, including identification time \(T_{Identification}\) and identification fees \(F_{Identification}\). Among them, the most important thing between IBC and IDBC is to discuss the number of INs, \(Number\). The more INs, the higher the credibility of the identification. At the same time, the increase in \(Number\) will also lead to an increase in identification costs. According to the negotiation result, the IBC fills these parameters into the ISC. Then, through the reputation-based node random selection algorithm in Section 4.1 to select INs. These INs will form an identification committee. The algorithm is implemented by the INPSC on the IBC, and the ISC is responsible for calling the algorithm. The design of the algorithm is biased towards nodes with high reputation values and is random; thereby, improving the credibility of IBC identification and realizing mutual trust between IBC and IDBC. IDBC will send the hash value generated by the data information and token stored in IPFS to IBC. It should be noted that IBC will send a token to IDBC. IBC will broadcast the hash to all INs of the identification committee. Each IN downloads data information through this hash value. If illegal data information is identified, INs can immediately report the data information to the IBC. ISC will start timing since the first IN report that the data is illegal, \(T_{Report}\). During this time period, the ISC will accept reports from other INs. When the timer ends, if the ISC receives no less than \(Illegal\) reports from the identification committee, the IBC will automatically confirm that the data information is illegal. Among them, \(Illegal\) is also the result of negotiations between IBC and IDBC, and IBC will put \(Illegal\) into ISC as an important parameter. It should be noted that \(Illegal\) must be more than half of \(Number\). The larger the \(Illegal\), the identification result of the IBC will be more credible. For example, if there are \(Number=5\) identification nodes in the identification committee, at least \(Illegal=3\) reports are required, and IBC can confirm that the data information is illegal. It should be noted that ISC will only receive identification reports from committee members, and reports sent by non-committee nodes will be considered illegal reports and will be rejected. Meanwhile, INs cannot report multiple times within the same reporting period. In a sense, the \(Number\) identification nodes constitute a \(Number\) man game. In this game, each IN is eager to obtain the maximum benefit. This paper designs the incentive mechanism, as shown in Section 4.2, and uses the Nash equilibrium principle of game theory to prove why INs must be honest players in the game; that is, they must honestly report illegal data information. Finally, the blockchain-based trust model for uploading illegal data identification will end in two cases. One case is that the identification time \(T_{Identification}\) has ended, and the data information is not illegal. Another case is that the data information is illegal information.