Algorithm 1 Procedure of registering a node.

1: Mapping $map$: $blockchain.address$→$physical.address$;  2: Mapping $state$: $blockchain.address$→0 $or$ 1;  3: while $true$ do /* The contract is waiting for a contract caller to trigger */ Input: Contract Caller’s Blockchain Address $ba$; Contract Caller’s Physical Address $pa$; Output: Registration Result r;  4:   $r\leftarrow null$;  5:  if $state\left(ba\right)$ = 1 then  6:     $r\leftarrow failure$;  7:  else  8:    $map\left(ba\right)$ = $pa$;  9:    $state\left(ba\right)$ = 1;  10:    $r\leftarrow success$;  11:  end if  12: end while