Blockchain technology has its roots in the late 1970s, when a computer scientist named Ralph Merkle patented the hash tree (aka Merkle tree). These trees are computer science structures that use encryption to link blocks together for storing data. In the late 1990s, Stuart Haber and W. Scott Stornetta used Merkle trees to implement systems that could not tamper with document timestamps. This is the first instance in the history of blockchain.

The technology has been evolving and has gone through three generations:

First generation -- Bitcoin and other virtual currencies

In 2008, an anonymous individual or group known only as Satoshi Nakamoto outlined the modern form of blockchain technology. Satoshi Nakamoto's Bitcoin blockchain concept uses a 1 MB block of information for bitcoin transactions. Many of the functions of the Bitcoin blockchain system remain central to blockchain technology even today.

The second generation -- smart contracts

In the years after the first generation of cryptocurrencies emerged, developers began to think about blockchain applications beyond cryptocurrencies. For example, the inventors of Ethereum decided to use blockchain technology for asset transfer transactions. Their key contribution is the smart contract feature.

The third generation -- the future

Blockchain technology continues to evolve and grow as many companies discover and implement new applications. Many companies are addressing scale and computing power constraints, and the potential opportunities in the ongoing blockchain revolution are endless.