A Fine-Grained IoT Data Access Control Scheme Combining Attribute-Based Encryption and Blockchain

Algorithm 1

Data Storage.

 Begin

  policy ⟵ (Owner, file)

  if key not exist then

   key = AES. Gen(Owner)

  end if

  encfile = AES. Enc(key, file)

  hashipfs = IPFS. Store(encfile)

  hashfile = SHA256. Hash(file)

  StoreCont(hashfile, hashipfs, policy)

  if PK, MK not exist then

   PK, MK = CPABE. Setup(r)

  end if

  enckey = CPABE. Encrypt(PK, key, policy)

 End