Improving Blockchain Consistency Bound by Assigning Weights to Random Blocks
This work addresses scalability issues in blockchain systems, offering a novel improvement to the Nakamoto protocol that could enhance performance for applications like cryptocurrencies.
The paper tackles the scalability limits of Nakamoto consensus by proposing Ironclad, a method that assigns different weights to randomly selected blocks, which significantly improves the consistency bound and allows for a faster block production rate under the same security guarantees.
Blockchains based on the celebrated Nakamoto consensus protocol have shown promise in several applications, including cryptocurrencies. However, these blockchains have inherent scalability limits caused by the protocol's consensus properties. In particular, the \emph{consistency} property demonstrates a tight trade-off between block production speed and the system's security in terms of resisting adversarial attacks. This paper proposes a novel method, Ironclad, that improves blockchain consistency bound by assigning a different weight to randomly selected blocks. We apply our method to the original Nakamoto protocol and rigorously prove that such a combination can improve the consistency bound significantly by analyzing the fundamental consensus properties. Such an improvement enables a much faster block production rate than the original Nakamoto protocol under the same security guarantee with the same proportion of malicious mining power (see Figure 1).