BSSPD: A Blockchain-Based Security Sharing Scheme for Personal Data with Fine-Grained Access Control

Algorithm 9

PolicyUpdate.

 Input: fid,

 Output: bool

1 ifmsg.sender is not _selfthen

2 throw;

3 else

4 data_row = data_table.find(fid);

5 ifdata_row == nullthen

6  returnfalse;

7 else

8  date_row.cf = ;

9  data_table.modify(data_row);

10  returntrue;

11 end

12 end