Security Features of Blockchain and How it Works
Hello people, hope you are doing fine, this my second article on blockchain. The year 2019 saw a surge in the use of blockchain across different industries and enterprises. It is no longer limited to investing and finance and has expanded to cyber-security, healthcare and agriculture. If you are interested to know how blockchain technologies are made secure, then this article is for you. To learn the basic concepts of blockchain, you can go through my previous article here.
When it comes to the security part, everyone is very conscious about their data security and privacy. Before a decade internet was not so reliable place to store any type of private data due to the number of hackers and pirated websites. But nowadays it is possible to store our sensitive and private data online without any type of hesitation in the Blockchain.
There are numbers of security layers which make blockchain so much secure that no one can manipulate any type of data inside the blockchain if data once added to the network. The 5 features that made the blockchain secure are
- Decentralized
- Cryptographic Hash
- Distributed Peer-to-Peer network
- Immutable ledger system
- Mining process
1. Decentralized:
Blockchain network is Decentralized. That means there is no particular administrator, who can manipulate any type of data inside the blockchain. All the nodes or people participate in this network get equal privilege. This makes the first security layer of blockchain.
2. Cryptographic hash:
Cryptographic Hash is one of the most important security features of blockchain. It can be considered as a fingerprint of a block. It is calculated using the SHA256 algorithm. This algorithm is open to all and anyone can learn it.
There are many features of this algorithm which make it very secure:-
2.1. Avalanche effect — By using this algorithm we can calculate a Hexa-Decimal number(Hash) for any type of data (audio, video, photo, etc) and even if we try to make a tiny change in the data which lead to the total change in the hash value. This is known as “Avalanche Effect”.
2.2. One-way computation — We can only calculate the hash value using this algorithm for any type of data but the vice versa is not possible. We can’t retrieve any type of data using the hash value.
2.3. Deterministic — It always compute a single value for the same data set. That means it never generates a random value for the same data.
2.4. Fast computation — The Time factor is the most important factor for computation of any type of algorithm and SHA256 also satisfy this criterion too.
2.5. Handling data duplication — As there are tons of data are uploading every day but the hash values are limited. So sometimes there may be a collision between two files, which have the same hash value. But it is rare. We can consider this situation as we all have our unique fingerprint but 1 among 60 million have the same fingerprint and doesn’t affect much more.
3. Distributed Peer-To-Peer network:
- Blockchain uses p2p network for data sharing and this can be considered as the next security layer of blockchain. If any malicious party wants to manipulate any type of data from blockchain then it has to change the data of more than 50% of nodes present inside that p2p network within a fraction of time.
- Even if anyone tries to manipulate the data inside any one of the nodes and succeeded, then the additional security layers come into play. These are immutable ledger system and mining process.
4. Immutable ledger system:
- For any type of data addition or manipulation, blockchain requires a certain amount of time (12–15 sec in Ethereum blockchain and 10 minutes in Bit-Coin blockchain). This prevents the hackers so that, they can not change a huge amount of data within a fraction of time.
- Even if any hacker succeed in any manipulation of data, but due to the Avalanche effect the next whole chain will change. As blockchain uses p2p network; with some interval of time all the nodes of the network sync data with each other. And when the manipulated copy of the blockchain try to sync inside the network, it gets rejected. That means it is quite impossible to change any data in the network.
5. Mining process:
- This is the process of calculating nonce for a particular block before deploying to the network. Nonce stands for “number used only once”.
- It adds an additional security layer for the network. As it requires great computing power for calculating the nonce value.
- Miners compute the nonce value for us. They try to find a nonce value whose corresponding hash value is less than a given target for that blockchain. When the miners get a correct nonce value for a block, that nonce value is called as “Golden Nonce”.
These are the key features which make the blockchain very secure.
I hope this article was informative. Stay tuned for more articles on Blockchain!
To explore more about security features of blockchain, you can give a view to the following articles :
https://www.ibm.com/blogs/blockchain/2017/12/blockchain-security-wmedium.hat-keeps-your-transaction-data-safe/
