Cost-Effectively Searchable Blackbox Data With Unlinkability Based on Public Blockchain

A blackbox data can be used to identify the cause of an accident. And we may need to find blackbox videos recorded by the third party to accurately analyze the cause of the accident. One of the basic requirements of blackbox data is integrity, and this integrity can be provided by uploading the data to blockchains. However, the existing blackbox data storage systems have two big problems, cost and privacy. The transaction fees are the costs necessary to upload data to the blockchains. The transaction fees of the major public blockchain are getting higher. Therefore, if a user uses Bitcoin or Ethereum to upload its blackbox video, the costs could be very expensive. On the other hand, the private information such as driving route could be revealed from the uploaded information to the blockchain. We suggest a cost-effective searchable blackbox data storage system with strong anonymity, i.e. unlinkability, using blockchains. In our scheme, the cost of registering a blackbox video is $\frac {cost_{tr}}{n}$ , where $cost_{tr}$ is the cost necessary to upload a transaction to a blockchain and $n$ is the number of uploading users at the same time. Therefore, our scheme is practical with public blockchains such as Bitcoin or Ethereum. In the paper, we suggest a cost-effective searchable black box data storage system with unlinkability using blockchains.