What is Blockchain and How it can Make Data Storage Secure?
By Learning Chain on ALTCOIN MAGAZINE
A blockchain is a list of records, called blocks, that are linked using hashes. Each block contains a hash of the previous block. Each block can contain one or more transactions.
Instead of storing data in the database directly, in blockchain, it is saved in the form of blocks and it creates a chain of blocks. This chain is IMMUTABLE ie. records can not be altered but append-only.
Blockchain Network
Blockchain network is created by participants. Each participant is a single organization. Each organization can run their one or multiple nodes in the network. There is no single owner of the network due to which network is decentralized. All participants can do transactions in a network. Each participant has a digital identity assigned to them by a valid CA. So any outside organization or person can not get in the network.
Features of blockchain
Immutable data
Data stored in blockchain is immutable. It means data stored in blockchain can not be altered. Records can not be updated to their original state, they are appended only. If there is any update in a record then there will be a new record. A new block will be added for any write operation.
Distributed Ledger
A ledger is an actual blockchain. In a blockchain network, every network participant will have the blockchain ledger. So ledger is not owned by a single organization. Every network participant will have the ledger and everyone knows what’s being added in a ledger.
Security
All data on the blockchain is cryptographically hashed. Hashing takes any input value and applies a mathematical algorithm to produce a new value of a fixed length.
Change of hash will result in a change in the hash of all blocks, which is not easy.
Digital identity
Each network participant has the digital identity assigned by a valid certificate authority. So any unknown company or node can not participate in the network.
Consensus
Blockchain works on a consensus algorithm. Let’s say if Org A wants to add some data into the blockchain then it needs to have approval to all the network participants. If all participants agree then only a write transaction will occur and a new block will be committed to the chain.
Why should I move to blockchain?
All the features explained above gives you a strong reason to move into blockchain. But still would like to give a real-world use case that can improve your understanding for blockchain.
In the healthcare world, Let’s say we are inserting a record of a patient ( who is on medication) into a traditional database. The record can have below fields
Patient Name
Medicine Name
Medicine Quantity
Date
Doctor
Disease
Now in the traditional approach record will be inserted into database.
Now the problem is if someone has access to DB, they can change the name or quantity of medicine easily and no one will be aware of it as record is changed directly into database. As this is a sensitive record this can lead to disaster situation for patients.
How Blockchain comes to the rescue?
In blockchain this can’t be done so easily. Even someone get access to blockchain but they can’t change the data directly as data is saved in the form of blocks. Also, every network participant has the same blockchain data. So they can validate the data any time. And further write operation will not occur as data-set is mismatched between network participants. This way records saved in blockchain are much secure compared to traditional database.
Thanks for reading.
