We are aware of the basic functions of most technologies, but a sizeable portion of users never express any interest in understanding technology in depth. For example, when sending an email, we know the data are received by the recipient, unless the transfer fails, in which case, we are left with the obvious option of clicking the ‘Retry’ button. But how much do we know about what happens between hitting the ‘Send’ button and the email landing in the recipient’s mailbox?
Similarly, with blockchain, we know the data are immutable, transparent and the entire system is very tough to hack. But how many of us know the underlying processes that make blockchain so secure? Let’s understand the features that make the technology near-impregnable.
In today’s world, with cyberattacks constantly on the rise, security is paramount as most of our data is digitally stored. The most noteworthy feature that makes blockchain secure is that it is based on a completely trustless system. The permissions to read and write the data on blockchain are equally distributed among all the users connected to the network and no user is given any special privileges when it comes to making any decisions.
The advent of blockchain successfully solved the Byzantine General’s Problem, a name given to the major drawbacks of a distributed consensus system. In the Byzantine General’s Problem, it is assumed that a general commanding multiple units (five, in our case) is about to launch an attack on a city. If all the general’s units launch an attack at the same time, they will win. If any unit defects or retreats, the attack fails.
The general sends a courier to deliver a message to all the units. A traitorous commander, who is the third to receive the message, whom we can call ‘X’, might change the command sent by the General without the knowledge of the messenger. The two commanders receiving the message after ‘X’ believe that it is from the General. This misinformation would lead to a failed attack due to poor co-ordination among the various units.
Blockchain can successfully solve this problem by introducing a concept called ‘Proof of Work’, which makes it essential for each message sender to attach a history of all previous messages and ‘spend some time’ on them, which is fixed at 10 minutes.
The purpose of ‘spending some time’ is to ensure that the sender has put in some effort to write the message and to make it easy to identify malicious or incorrect data. A very basic example in the case of the Byzantine General’s Problem would be where each commander is required to write the numbers 1-500 before confirming and sending the message to the next commander. It would certainly take some time to write the numbers but the verification would be quick and easy.
Since each commander spends ten minutes on a message, ‘X’ would have to change his message and those of the two commanders who preceded him because the ‘Proof of Work’ concept requires a log of all previous messages to be uploaded. To successfully change the message, ‘X’ would have to work for twenty minutes plus an additional ten minutes to create his own message, amounting to a total of thirty minutes’ worth of work in the ten minutes allotted to him. This way, altering the attested data is practically impossible as even if ‘X’ does upload an incorrect message, the rest of the commanders can ignore the incorrect message and follow the one attested by most commanders.
No single user or organisation is given supreme control of the database. Having a decentralised design, it does not have a single point of failure. Even the loss of power or the total failure of a few devices connected to the blockchain network won’t have any effect on the data stored as the entire database or parts of it are stored across all devices connected to the network.
Since blockchain is decentralised, it cannot be controlled by the government. State intervention usually results in some domains and websites being shut down as the government believes such websites do not follow established rules and regulations. The most famous example in recent times is the search engine Torrentz.eu. At present, torrent sites are the closest thing to a decentralised system on this scale.
Also, the data stored on blockchain are cryptographically secure, and the public and private key cryptography ensures that the data is received only by those it is intended for. The cryptographic techniques also help users maintain privacy by allowing them to remain pseudo-anonymous while sending and receiving data across the network. Due to its decentralised architecture and the cryptographic coding used in its design, the blockchain network is mathematically very tough to hack into—the cost of hacking such a system skyrockets, with the data stored on each node properly synchronised with the entire database.
All the above features make blockchain a practical option for a user who wishes to store his data safely. The data stored on blockchain cannot be edited or tampered with in any manner. New or updated data can only be appended onto the blockchain later.
Realising the plethora of advanced security features offered by this technology, many companies have invested heavily in the research and development of blockchain-based applications. It is slowly being integrated into our daily lives as companies are exploring both fintech and non-fintech applications of blockchain, which might completely change the way we look at digital data storage.
Nikunj Jain is co-founder and chief strategy officer at Darwin Labs. The Gurgaon-based studio and incubator develops product and services on blockchain, virtual reality and ad-tech. It also helps businesses adopt these technologies.