Blockchain-Based Privacy Protection Scheme for IoT-Assisted Educational Big Data Management

Algorithm 1

Data center control utilities.

1: Initialization: Synchronize the blockchain object bc with blockchain nodes to get the newest state of the access model. Connect to the MongoDB database and get an object .

2: // verify the permission of an access request

3: function VERIFY(uid, hash, sig)

4:  // check if the user is offering correct signature to be identified as user uid

5:  if.verifySignature(uid, sig) == falsethen

6:    return false

7:  end if

8:  role = bc.getRole(uid)

9:  tags = bc.getTags(hash)

10:  fortagin tags do

11:   if.findState(role, tag) == falsethen

12:    return false

13:   end if

14:  end for

15:  fortag in tagsdo

16:   if.findState(role, tag) == truethen

17:    return true

18:   end if

19:  end for

20:  return false

21: end function

22: function RUNSERVER

23:  whiletruedo

24:    uid, hash, sig, addrFrom = getRequestParams()

25:    if verify(uid, hash, sig) == false then

26:     sendMessage("Authorization failed.")

27:    else

28:     sendMessage("Authorization suceed.")

29:     data =.getData(hash)

30:     sendData(addrFrom, data)

31:    end if

32:   end while

33: end function