The Blockchain Trilemma was a challenge that prevented large blockchains like Ethereum from having a high TPS. It was considered to be a trade-off where you could only choose two among the three: SCALABILITY, SECURITY, and DECENTRALIZATION.
- If the blockchain was secure, then it had to be decentralized and have a high number of independent nodes. This reduced scalability since it took a long time to verify transactions by passing them through a majority of nodes.
- If the blockchain was highly scalable and yet secure, it had to compromise on decentralization because such a vast network would hinder speed.
- If it was scalable as well as decentralized, then it had to simplify its transaction verification process which then made it less secure.
Solution
The solution for the blockchain trilemma was discovered when Ethereum brought forward its Surge series of Upgrades. These upgrades aimed to scale Ethereum’s network speed from 15 TPS to over 100k TPS.
Another solution that was implemented in Bitcoin was the Lightning Network which provided a temporary ledger that is shared between two network participants who transact with each other. After transactions are finished, this ledger is then summarized (hashed) and its summary data is added to the Bitcoin blockchain as a single transaction.
After these solutions were implemented, the blockchain trilemma seems to have been finally solved.