Algorithm 1: ProofRecord function of the content

Input: IPFS_pc

Output: OwnerAddr,IsExist

1 function ProofRecord (IPFS_pc)

2 Query the global mapping IpfsToAddr to find if IPFS_pc already exists

3 if IpfsToAddr [IPFS_pc] ≠ 0 then

4 The IPFS_pc already exists

5 return IpfsToAddr[IPFS_pc], false

6 else

7 Let IpfsToAddr[IPFS_pc] ← OwnerAddr

8 return OwnerAddr, true

9 end if

10 end function