Blockchain for Data Storage
By Shreyas Nanaware
Written solely by the student, Shreyas Nanaware, who is responsible for all the glory and the pitfalls of the write up. This was part of citizen science effort under the leadership of Sukant Khurana
Traditional Cloud Storage
The simplest way to store your data or files online is using cloud storage. However, with increasing demands and usage, these centralized systems have become major targets for hacks and data breaches. This makes the data vulnerable and prone to tampering. Even if encryption is used, the keys are stored with the cloud service provider. This reduces the security provided by encryption. Another problem is that the data is usually not encrypted during transmission. The data can hence be intercepted during transmission from the user’s computer to the cloud.
Using Blockchain
The solution to make cloud storage faster and more secure is using blockchain. Blockchain is a database or ledger that is shared across a network. This ledger is encrypted such that only authorized parties can access the data. Since the data is shared, the records cannot be tampered. Thus, the data will not be held by a single entity. It provides many areas of application and here we see how it will serve as a better alternative to cloud storage.
By decentralizing data storage, we greatly improve the security of the data. Any attack or outage at a single point will not have a devastating effect because other nodes in other locations will continue to function. Instead of uploading your data on a centralized cloud, you distribute across a network over the world. The cloud is shared, making it impossible to tamper and encrypted in a manner that only the owner can view the file. This is useful to make important records safe and decentralized.
How does it work?
To achieve this, we first break the data into small chunks. Then these chunks are encrypted and uploaded onto the blockchain. They are distributed in a manner that all chunks are available even if part of the network is down. This is also known as redundancy. The system ensures adequate level of redundancy.
The first step is file sharding. The file is divided into many small pieces. The shards can be sent and recalled parallely, making file transfer quicker. Sharding would require a small percentage of nodes to see and process every transaction, instead of all nodes as blockchains are designed today. No entity has the entire file. Only the uploader knows where all the shards are located. A cryptographic hash table is used to locate all the shards for a file. The uploader is the sole owner of the private key required to discover all the shards. To take security further, the individual shards are encrypted as well. Thus, even the chunks of data cannot be read by the nodes in the network.
The shards are stored together by using a technique known as swarming. A swarm is a large group of nodes which store and manage data.
Advantages:
Using peer to peer networks can boost download speeds.
The data is distributed globally making it is highly available.
The data is sharded as well as encrypted making it highly secure.
It can be extremely cheap.
Conclusion:
It is easy to see that using blockchain will make file storage cheaper and much more secure.
References:
http://www.dataversity.net/blockchain-can-used-secure-sensitive-data-storage/
http://dataconomy.com/2018/01/blockchain-data-storage-decentralized-future/
