# Blockchain-Based Model for Incentivized Cyber Threat Intelligence Sharing
## 3 Proposed Solution
### Building of Motivation and Trust  
#### 3.2.1 Cost Compensation and Reputation  
The cost compensation is the first factor to consider in decentralized data-sharing networks, as the resulting costs can discourage data providers from sharing data. We propose a model for incentivized CTI data sharing, which seeks to provide a profit to both the data provider for sharing CTI data and the CTI data consumer for an acquaintance with the provided data.  
The proposed model for incentivized CTI data sharing has three goals: (1) to cover the costs of sharing CTI data incurred by providers; (2) to promote the use of the shared data by CTI data consumers; and (3) to provide some degree of trust in the dependability of the CTI data provider and their shared CTI data. To establish the first two goals, a monetary reward is used. To establish the third goal, a reputation reward, which is expressed in terms of rating scores, is applied. Data providers can benefit twice, receiving a monetary reward to cover the cost of publishing data and receiving recognition from the community. CTI data consumers can also benefit twice, receiving a monetary reward for re-using shared data and receiving recognition for being an active member of the community.  
The rating scores show the reputation of the users and are used to predict trust in a presented product. The presented product is either the shared CTI information itself or a review of it. Of course, this prediction is always subjective. No one can ensure that a user with a high rating value will not provide a product of low quality. However, reputation schemes promote cooperation and encourage user activity, thereby increasing  
Figure 1: Pillars of the model.  
decentralization. Moreover, the CTI data producer is discouraged from providing low-quality CTI data since they will be punished by receiving a penalty score.  
To start CTI data-sharing activities, the interested parties must invest in them. Funds must be raised and shared according to the activities of the interested parties. One of the ways to raise the funds to support the defined goals is a subscription fee. Community members who are interested in sharing CTI data must subscribe to a CTI data-sharing network and pay the subscription fee, which can be either monthly or annual, depending on how long a member of the network requires access to shared CTI data.  
The members of a CTI data-sharing network can interchangeably accept the roles of both CTI data producer and CTI data consumer. CTI data producers are encouraged to provide CTI data; therefore, a reward score is assigned to the CTI data producer for just one single act of CTI data provision. The quality of the CTI data is not taken into account yet. Nevertheless, the quality of the CTI data must be evaluated. The community should be self-organized in such a way that the decentralization of the network is increased. We must avoid using a trusted third party, which is a component of centralization, to evaluate the quality of shared CTI data. This work can be carried out by CTI data consumers. Motivation is needed to encourage CTI data consumers to review CTI data. A reward score should be assigned to consumers who express their desire to utilize the produced CTI data and to write a review of it. The CTI data consumer reward score is much lower than that of the CTI data producer.