by Lumai Mubanga
The greatest benefits blockchain has introduced into database systems is immutability. Unlike conventional databases, the idea behind immutability is that, once data is committed to the blockchain or to the ledger, it is there permanently. While data can be added and “updated”, it cannot be deleted or edited. However, does it guarantee the accuracy of the data?
What sets blockchain apart is that new records can be created in the database. These records can also be read. Does the fact that data can be added mean that it is accurate and will remain so? Does this mean that data cannot be edited or upgraded to indicate genuine changes? Blockchain is designed to permit the addition of new data sets to indicate that something has changed about it. This though is a totally new record, not edited. This is the immutability, which makes blockchain trustless, indicating that players on the platform do not need to trust each other, but that, they can trust the data on the blockchain.
By design, immutability is perceived as a very inefficient solution. This is because of the repetitive nature it operates. The same work done on one node has to be repeated on every other node on the network. On the other side, this is done to make it literally impossible to change information on the blockchain. Any changes need at least 51% consensus from the entire network.
To put this in context, a huge network like the bitcoins with thirty thousand users, for example, any changes will need to be done on at least fifteen thousand nodes. That is impossible from a practical point of view but not for a determined hacker.
Immutability and GIGO
Garbage in Garbage out – GIGO is a computer term which means the computer accepts anything inputted into it; wrong or right. Blockchain will give you immutable data of what is posted, wrong or right. It does not validate. It rests upon anyone accessing that immutable data to confirm if it is true. So, while the data is immutable, it is not guaranteed to be accurate, it is a factor of GIGO. The only validation is that it has not been changed from the original.
Immutability and Cryptographic
Cryptographic hashing is one inbuilt design that ensures blockchain is not broken or tampered with without the network noticing any changes. It allows blocks to be connected to each other such that, any changes made on one block would directly affect all other interlinked blocks. While this does not guarantee the accuracy, it does promote immutability of both old and new data.
So, immutability is basically a virtual impossibility of any blockchain or platform user coming up to edit any information already appended on the chain. It preserves what is posted, wrong or right and any changes have to be made on a new block. This leaves only two options to data on the blockchain, add and read. The concept of delete and edit is not part of the blockchain design.