Of late there has been a lot of interest in Blockchain technology and many researchers are looking at ways in which Blockchain can be used in geospatial systems. This is expected because geospatial systems have made very good use of computing technology right from databases to networks and the Cloud. Geospatial technology is increasingly becoming embedded in other systems like BIM, BI, BPE and so forth. Therefore, it is only some time before it embraces Blockchain technology.
In this blog, the discussion is on Public BlockChains. There is something called Private BlockChain which has many other features, but as it is at the development level we will leave it out of the current discussion. The Chain in BlockChain is the chain of transactions in the form of ledger entries about assets which could be money, imagery, data, maps, documents, etc. In reality what is actually transacted are tokens containing the metadata of the assets. The actual physical transfer happens separately. Block refers to the grouping of transactions related to each other. A way of looking at a BlockChain is to consider it as a ledger where all transactions are entered.
In what way is a BlockChain different from a database?
BlockChains are open to all members, therefore the ledger of transactions are available to all members. There are no centralized administrators as it is a peer-to-peer network. Every transaction entered in the BlockChain is verified and approved by consensus among the members. However, there are validators called ‘miners’ who can review the transactions and validate them. The two key characteristics of BlockChains are trust and immutability. Just like in a business where transactions are based on trust so also the members operate on trust. Immutability is ensured by the prevention of a record of a transaction being modified or deleted. When a member makes a transaction it is date and time stamped and is accompanied by a key generated by the computer using the members private key.
Every subsequent transaction is similarly stamped and a new key is generated which includes the earlier key. Thus any attempt to hack will require to unravel the transactions key by key which will be an impossible task. Assuming that even that happens, the hacked ledger will differ from the other copies and after a process of consensus will be removed and replaced by the consensus copy. What happens if the change is genuine? Well, there is a possibility of ‘forking’ and the creation of two networks from one. We will discuss these complications in another article.
When to use a BlockChain?
When there is a multi organizational network that needs to work without intermediation, which can tolerate openness and is not performance driven, it would be an ideal candidate for BlockChain implementation. A large network where the members do not know each other sufficiently to be able to assign trust a priori is an ideal situation for BlockChain implementation. However, if there is a need for central control, confidentiality, fast performance and high scalability then it might make sense to go for a normal distributed database.
The most visible implementation of BlockChain is the BitCoin network. Here a potential member has to open a wallet to which the system assigns a private key. The member can now transact with others on the network, paying by BitCoins for goods, services, data, documents, etc. We may soon see banks going the BlockChain way, not immediately but not in a very distant future either.
In geospatial terms, two domains which are attracting BlockChain implementation are land transactions and data repositories. In the case of land records, there is no established trust between the participants and there is a need for openness. The weakest link, the mediator in the form of the record officer (talati – in India), can be eliminated, preventing spurious transactions by immediately trapping and replacing it with the consensus copy. In the case of data repositories like NSDI, the need for a centralized service and the loss of synchronization between data stores can be eliminated by having all metadata repositories and their clients who could be data generators, value adders and customers on a BlockChain network. However, the biggest potential application of BlockChain lies in the implementation of the Internet of Things. Imagine a dam operated automatically based on an AI program which factors in many variables including data from sensor networks. A rogue sensor which indicates a heavy rainfall in the catchment could upset the model but if the sensor and the automatic system are on a BlockChain the rogue sensor input can be trapped and eliminated even before it reaches the model.
BlockChains are evolving and it would be wise for the geospatial world to keep abreast of the technology, try out pilot applications and thus get in at the ground floor of what today appears to be a future game changer.
The author would like to acknowledge the help of Mr. Kartik Kumar, Co-Founder of SpatialTrust.com in preparing this article.