Must fast blockchains compromise on security? Deciphering the blockchain trilemma.
Experts interviewed by crypto.news believe that the blockchain trilemma, coined by Ethereum co-founder Vitalik Buterin in 2017, provides insights into the challenges faced by developers in creating distributed ledger systems. According to Buterin, developers must prioritize two out of three key features and make tradeoffs. Luke Nolan, a research associate at CoinShares, agrees with this perspective, stating that achieving all three features to their fullest extent is a challenge. He emphasizes that developers often sacrifice certain aspects or both when optimizing one feature.
Alex Dulub, Founder of Web3 Antivirus, suggests that increasing the speed of a blockchain can compromise its safety. He believes that solutions like Layer-2 (L2) networks and sidechains, which handle transactions outside the main blockchain, can improve speed and scalability but may introduce new risks. Dulub identifies smart contract bugs, centralization risks, and potential attacks as the main vulnerabilities for blockchains aiming to improve all three aspects.
Neville Grech, the founder of Dedaub, a blockchain security firm, points out that increasing parameters like block size and frequency to enhance speed may require more computational power, bandwidth, and storage than average nodes can handle. This could result in a more centralized network structure, with only a few nodes fully participating in the blockchain. Grech warns that adjusting the validation process to speed up a network could expose the blockchain to vulnerabilities and validation disputes, creating temporary forks. He also notes that reduced participation of nodes and validators in the verification process could compromise the network’s decentralization and the integrity of the blockchain.
To illustrate, the Bitcoin network processes an average of 8.35 transactions per second (TPS), while centralized money transmitters like Visa have a TPS range of 1,500 to 2,000. Zcash’s blockchain operates at an average speed of 26 TPS for non-shielded transactions but faces the risk of a 51% attack due to the majority control of its hash rate by the ViaBTC mining pool. Solana, on the other hand, boasts a current real-time TPS of 772 and has demonstrated high stability despite experiencing major outages in the past.
According to Nolan, the primary tradeoff made with Solana was decentralization, as security came at a more minimal tradeoff. The cost of running a Solana validator is also high, making it expensive for the general public to operate a validator and posing risks of centralization. Solana currently has a total of 2,919 nodes, while Ethereum has around 7,000 nodes.
Companies are introducing creative solutions to challenge the blockchain trilemma and balance scalability, security, and decentralization. Some of these solutions include L2 networks, consensus mechanism changes, Segregated Witness (SegWit), sharding, and rollups.
In conclusion, the blockchain trilemma highlights the challenges faced by developers, and tradeoffs must be made to optimize certain features. Careful design, rigorous testing, and ongoing research are crucial in managing these challenges.
