The Blockchain Trilemma
Since the first generation blockchain, Bitcoin, there have been countless studies to make desirable distributed ledgers. Ethereum opened the era of second-generation blockchain with the concept of a smart contract. In the competition for the third generation blockchain consensus nowadays, various solutions are proposed and now running, such as DPOS(EOS), FBA, SCP(Stella), Ouroboros(Cardano, ADA), and so on.
Every consensus algorithms have to consider the trade-off between scalability, security, and decentralization, so-called blockchain trilemma. No consensus algorithm is perfect for the whole factors, but they are trying to seek the compromise.
STEP; Sybil-attack Tolerant Equality Protocol
Sybil-attack Tolerant Equality Protocol(STEP) is a consensus algorithm based on DPOS, aiming for a next-generation blockchain. DPOS is a consensus algorithm used in EOS, which is in the top 5 for the market capitalization. DPOS is focused on scalability in the blockchain trilemma, which means that it is somewhat centralized. This centralization is based on its unique voting system depending on one’s stake.
STEP is designed to balance the three factors of blockchain trilemma. In other words, STEP is a consensus algorithm that decentralization and security are enhanced from DPOS. Instead of electing block producers(BPs) by voting, STEP selects BPs randomly per round. The random selection causes decentralization we say as ‘equality.’ We are now studying the random selection algorithm appropriate to the blockchain environment.
The reason DPOS does not select BPs randomly comes from security. The BPs selected in random are not trustful to manage the whole blockchain. That is, equality can bring about vulnerability, especially on Sybil-attack. We are also studying various systems to secure the whole blockchain system without the sacrifice of equality.