Manual on the Digiland Land Ownership blockchain and its Explorer
Main fonctionality of the Digiland Explorer
The Digiland Explorer provides an interface to the data of land titles which are decentrally stored
on a public blockchain. The content being stored on the public blockchain is a digital fingerprint
of the data related to real land titles. The concept of a digital fingerprint is what is being
referred to as a hash. The advantage of hashing technology in this case, is that if any underlying
data has been wrongfully altered, the resulting hash would not correspond to the hash originally
stored on the decentralized blockchain.
The beauty of the decentralized nature of the blockchain is that the original hash can impossible be altered or changed by anyone therefore providing an undeniable source of truth and authenticity. By providing access to the explorer Digiland makes its land title platform transparently, independently and cryptographically auditable by anyone who wants to scrutinize the underlying system. Digiland highlights that the purpose of the explorer is to create legitimacy but that the average user does not have go through any of the content of this page but can confidentially rely on the data that he sees when using the mobile app or the web app to scan a land title.
Digging into the architecture:
Digiland runs a centralized side chain on its servers with regular data submissions
to the globally decentralized Etherum network.
Every land title registration received by the government gets registered as a transaction on
Digiland’s sidechain. The data related to a certain land title, which Digiland receives from the
Bangladeshi government , gets hashed to what is referred to as the transaction content hash. That
content hash is taken together with the timestamp of the transaction and gets rehashed to what we
refer to as the transaction hash.
Whenever the sidechain registers 10 transactions a new block containing these 10 transaction is created on the sidechain. The block contains a inner hash which results out of the 10 transaction hashes of its underlying transactions. Finally the inner hash is taken together with the previous block hash and gets hashed to a new block hash. This is what is referred to as sidechain, as despite its centralized nature the data is interlinked by a chain of hashes.
How does Digiland decentralize the data and therefore ensure integrity and transparency?
This is where Etherum public blockchain comes into play or what Digiland refers to as its main chain.
Whenever a block is created on the sidechain its blockhash gets submitted to the globally decentralized
and immutable ledger of the Etherum network. The location and content of that submission can be verified
on the Etherum network by any user and a direct link to that location is provided on Digilands platform.
Therefore whenever data from the sidechain is being altered it would not match with the hash that is
stored on the Etherum blockchain and therefore would not be trustworthy.
In order to ensure that the sidechain remains integer and in line with the immutable data stored on the etherum blockchain Digiland runs an automatic comparison of database against current state of the public blockchain in the back on a regular basis. In case any mismatch found or in case Digiland’s Servers get compromised a warning is shown to the user about the specific land title he is looking at. In that way any Bangladeshi citizen can easily and reliably use the system without going through the auditing process ( documented below) himself.
How to audit Digiland's platform using the Explorer
The below instructions allows anyone to audit and verify that the data he sees is accurate and corresponds
to what has originally been stored on the blockchain. When scanning a land title or manually going to an
individual land transaction, the user is being led to the screen below. Pic 1 In the lower part the user can
see the data related to the land title he is interested in. He can now copy the data ander the source data
and paste in into the hashing area to calculate its hash. The result should correspond to the Content hash
listed above In a second step the user can copy the transaction hash source data into the hashing field and
calculate its hash.
The result should correspond to the transaction hash.As the data on the transaction level has now been verified, the next step is to verify that this has been registered on the block level as well. Thus the user should verify if the transaction hash is part of the block source hash. If it is part of it he can take the block source data and copy it into the hashing area to calculate its hash. The resulting output should correspond to the inner block hash. If that is the case the user can as a last step check if the block hash source data of which the content hash is part of leads to the block hash.
If all these checks are made we can be certain that the final block hash is unique to the data that the user is seeking to verify. Finally he can verify by if that block hash which is unique to the data of the land title he was verifying, corresponds to what is being decentrally stored on the etherum network. He can view this by clicking on the link provided under “Status”. The link leads him to etherscan the official explorer of the etherum network. Here the user can verify that the unique block hash resides within the decentrally immutable etherum public blockchain, thereby being confident that the data has not been altered.
Blockchain: A blockchain is a growing list of records, called blocks, which are linked using cryptography. Each block contains a cryptographic hash of the previous block a timestamp, and transaction data. By design, a blockchain is resistant to modification of the data. It is “an open, distributed ledger which accepts new data through a waterproof consensus mechanism.
Hash: A hash is a function that converts an input of letters and numbers into an encrypted output of a fixed length. A hash is created using an algorithm, and is essential to blockchain technology. In the context of cryptocurrencies, the transactions are taken as an input and run through a hashing algorithm which gives an output of a fixed length. In the context of Digiland’s side chain land title related data is taken as an input and run through a the MD5 hashing alogorythm.