The blockchain trilemma is the set of three issues that plague blockchains: decentralization, security and scalability.
The blockchain trilemma is a concept coined by Vitalik Buterin that proposes a set of three main issues — decentralization, security and scalability — that developers encounter when building blockchains, forcing them to ultimately sacrifice one "aspect" for as a trade-off to accommodate the other two.
It is a widely held belief that decentralized networks can only provide two of three benefits at any given time concerning decentralization, security, and scalability.
However, ongoing innovation across the decentralized ecosystem has led to a diverse range of Layer-1 and Layer-2 solutions that are overcoming these obstacles to solve the trilemma once and for all in the following fashion:
Decentralization. Rather than being managed by a single entity, blockchains distribute control over the network equally to all participants.
- Security. Blockchain networks should have ironclad defences that prevent malicious entities from taking over.
- Scalability. Blockchains should support an enormous number of transactions and users without faltering by increasing fees and transaction times.
For some in the industry, achieving all three aspects is an impossible feat that will never be achieved, at least not in the near future. However, there are still ambitious developers who believe that blockchain networks can indeed have all three and more. One example of a cryptocurrency project touting that they’re solving the blockchain trilemma is Algorand.