Some time ago, we conducted an in-depth test of a privacy protocol's Seal scheme, paying special attention to how it handles the on-chain storage of medical data. Looking at the real-world scenario of the CUDIS project, the process of patients uploading medical reports is quite interesting— the system splits the data into 20 fragments, each encrypted with the patient's wallet address, and then stored on different nodes. As long as a doctor is authorized, their wallet can decrypt and reassemble these fragments.

The actual test results were as follows: even if 6 nodes are attacked simultaneously, the complete data cannot be reconstructed. Moreover, the key point is that the blockchain only records the storage addresses of these encrypted fragments, making the original information completely invisible. This "fragment encryption + access control" combined solution not only meets privacy requirements but also considers compliance. From the perspective of medical data protection, this approach indeed has the potential to become an industry standard.