# A New Blockchain-Based Multi-Level Location Secure Sharing Scheme
## 4 Our Proposed Scheme
### Our Proposed Scheme
#### 4.2.2 Location Record
The main limitation of our proposed scheme is that \(Fnode\) must not collude with \(LD\). \(Fnode\), in this paper, can be an node from a BT private network or a DHT network like [32], and it can freely choose whether to provide services for benefit. It is \"honest but curious\", similar to a cloud data service provider, but much cheaper. In other words, it will not betray the data owner and illegally share information with others. However, it should be prevented from prying into the privacy of the data owner. The system should choose as trustworthy a \(Fnodes\) as possible, such as those whose social credibility is high. How to improve the query efficiency in our proposed scheme is a problem that we can continue to study in the future. For \(LD\)s, maintaining the blockchain is not their original purpose. They tend to be light nodes rather than full nodes, that is, they will not reserve complete blockchain data. Therefore, they query the corresponding blockchain data through other full nodes, similar to SPV-based queries in the bitcoin [29]. It is meaningful to improve the efficiency of this indirect query. Conceptualization, Q.W. and T.X. ; methodology, Q.W. and T.X. ; validation, T.X., Y.R. and L.Y. ; formal analysis, T.X. and G.M. ; investigation, T.X. and G.M. ; writing--original draft preparation, Q.W. and T.X. ; writing--review and editing, Q.W., L.Y. and G.M. ; visualization, T.X. ; supervision, Y.R. ; project administration, Q.W. ; funding acquisition, Q.W. All authors have read and agreed to the published version of the manuscript. This research was supported by Zhejiang Provincial Natural Science Foundation of China under Grant No. LY19F020039. Data Availability Statement: Data sharing not applicable. The authors declare no conflict of interest. ## References

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