Blockchains are capable of processing a limited number of transactions per second. The Bitcoin network, for example, can process about seven transactions per second. If the goal is global adoption of blockchain technology, it must be able to process a much larger volume of data and offer faster transactions. This way, more people can use the network without slowness or high costs involved. However, the design of many decentralized networks means that increasing scalability decreases decentralization or security. This problem is known as the blockchain trilemma. Programmers who are trying to solve this problem are experimenting with different consensus mechanisms and scalability solutions, such as sharding, sidechains, state channels, and the Bitcoin Lightning Network (layer 2).

The term trilemma was popularized by Ethereum co-founder Vitalik Buterin. The blockchain trilemma is the three desirable elements in a blockchain: decentralization, security, and scalability. The blockchain trilemma refers to the idea that it is difficult for a blockchain to achieve ideal levels of all three properties simultaneously. Focusing on one of them usually causes the weakening of another.

The most obvious and basic solution to the problem is to reduce the number of participants who confirm and add data to the network, in exchange for greater scalability and speed. But this harms the decentralization factor, as control would be in the hands of a smaller number of participants. And it would also cause a weakening of security, as with fewer participants there would be a higher probability of attacks. There is no single miracle solution to the trilemma. But given the importance of solving this problem, there has been a series of different approaches in the community with interesting results.

The scalability trilemma prevents blockchain from fulfilling its potential as a technology to change the world. If blockchain networks are only able to handle a small number of transactions per second to maintain decentralization and security, it will be difficult to achieve mass adoption. However, the solutions presented by programmers who are looking to solve this problem suggest that the technological advances already made by blockchain technology are on the right track. In the future, networks will be able to handle a much larger volume of data.