## 4 Approach
### Safe Place Administration Distributions  
After registration using easy validation and identity verification, leading to the final selection, the buyer has already validated their intention to buy without any face-to-face contact with other participants. For the distribution of the real estate to the buyer, when they have already been approved to receive the property, a smart contract is generated to conduct the distribution process.  
The first step in the process is the validation of the buyer's identity before delivery. It is performed by the seller using the buyer's registration, for example, a QR code that contains the hash of the blockchain transaction, the address of the smart contract, the hash of the personal identification number, and the hash of the password key. The smart contract that manages this process is presented (Algorithm 2). First, the validation of the buyer using the information of the QR code and the data registered in the blockchain is confirmed (lines 4-10). This is achieved in the chain by offering the two hashes (the BI hash and the PK hash) as inputs and checking the obtained root hash against the buyers' record stored in the chain. Both the buyer and the smart governance must acknowledge the management in the chain (lines 11-22) by signing the associated blockchain transaction. When both firms have been registered, the property lot size is reduced and the association between the Buyer Hash (BI) and the property lot is registered (lines 19-20). Any buyer who has received their place to live can record their feedback and prioritize buyers who were unable to purchase the home. By directly registering the priority on the chain, the information is difficult to change and censor. The buyer will sign a blockchain transaction that is authenticated and authorized (line 6), verified with the managed house from the specified place (line 7), and correlated with reports from the other buyers. As a result, the registered priority is stored in a string as a transaction (line 8).
```
1:State:
2:MAP (bytes Place_LID, MAP (bytes hashBI, MAP (string role, address Participant))) _administrationESignatures
3:MAP (bytes hashPI, bytes location_LID)_administratedLocation
4:Function checkIdentity//check participant identity
5:Input: hashBI, hashPasswordK, hashLevelStatus
6:Output:
7:Begin:
8:hashBuyer \(\leftarrow\) keccak256 (concat (hashBI, hashPasswordK, hashLevelStatus))
9:validationStatus \(\leftarrow\) _registerRequest (hashBuyer)
10:End
11:Function signDistributionPlace
12:Input: msg.sender, Placed, hashBI
13:Begin:
14:IF msg.sender is SmartGov **THEN**

_administrationElecSign[PlacedId][hashBI][SMARTGOV] = msg.sender
15:ELSEIFmsg.sender is Buyer **THEN**

_administrationElecSign[PlacedId][hashBI][BUYER] = msg.sender
16:ENDIFIF_dministrationElecSign[PlacedId][hashBI] [SMARTGOV] exists
17:&&

_administrationElecSign[PlacedId][hashBI] [BUYER] exists
18:

_administrationElecSign[hashBI] = Placed
19:

_LocationNumber[PlacedId].size =_PlaceNumber[PlacedId].size-1
20:ENDIF
21:End
```  
**Algorithm 2** Smart contract: Safe living place distributionMost importantly, the permissions of the blockchain should be controlled by the public authority. In this way, it can be ensured that real estate transactions meet the minimum legal standards. The consensus should be administered by the government (smart government) where the public authority, regulators, laws, etc., can validate any change in the blockchain. All transactions should only be authorized when they meet the legal requirements of the country. The revision of the contract, control of the price of the property, etc., are attributions of the governments. Access to the registry for the purchase of real estate and the entire process described in this work must be through the official and legal services offered by the government. Some proposals to improve security in the blockchain and its encryption [54; 55], together with consensus mechanisms [56; 57], can also be applied.