Algorithm 1 Save and Search of Hot & Cold Blockchain

Input: Hot_Tx // Investigation and identity transaction     Cold_Tx // Evidence video and identity transaction     K // User Private key output: Save Success or Failure      Search Result of Hot_Tx and Cold_Tx

01 Hot_ledger [] ← NULL // Hot Blockchain Ledger 02 Cold_ledger [] ← NULL // Cold Blockchain Ledger 03 D [] ← List // User Digital Certificate 04 function Save(Hot_Tx, Cold_Tx, K) 05   I ← 0 // User index 06   V ← 0 // Valid flag 07   F ← 2 // Full flag 08   while D[I] do 09    if D[I] ∋ K && !is Empty(HoT_Tx) 10      V ← V + 1 11      Append(Hot_ledger [I], HoT_Tx) 12    end if 13    if D[I] ∋ K && !isEmpty(Cold_Tx) 14      V ← V + 1 15      Append(Cold_ledger[I], Cold_Tx) 16    end if 17    I ← I + 1 18    end while 19   while true do 20    if V = F return true 21    else return false 22    end if 23   end while 24 end function 25 function Search(HoT_Tx.ID and RNN, K) 26   I ← 0 // User index 27   R1 ← 0 // Hot_Tx 28   R2 ← 0 // Cold_Tx 29   while D[I] do 30    if D[I] ∋ K 31      if Hot_Tx[I].ID and RNN = Hot_Ledger[i].IDand RNN 32       R1 ← Hot_Ledger[I] 33      end if 34      if R1. EVI_ID = Cold_Ledger[I].EVI_ID 35       R2 ← Cold _Ledger[I] 36      end if 37     I ← I + 1 38   end while 39   return R1, R2 40 end function