Signature-free blockchain methods cut consensus delays significantly
Simple and Fast Signature-Free Blockchain Consensus
Distributed, Parallel, and Cluster Computing
Summary
Blockchain systems need to agree on the order of transactions, which often requires complex digital signatures that could be vulnerable to quantum computers. The authors present new ways to reach consensus without these signatures, making the process faster while keeping security guarantees under certain network conditions. Their methods reduce the number of communication steps needed to confirm transactions and work efficiently even when some participants behave badly. These protocols use a new concept called view agreement to coordinate participants reliably.
What this means in practice
- •For blockchain engineers: Implement faster consensus protocols that avoid expensive cryptographic signatures while tolerating some faulty nodes for improved transaction confirmation speed.
- •For distributed systems developers: Use signature-free consensus mechanisms in distributed ledgers needing low-latency agreement without relying on computationally expensive signature verification.
Authors
Giuliano Losa, Xuechao Wang, Zhuolun Xiang, Qianyu Yu
Abstract
Signature-free protocols avoid the cost of post-quantum signatures. We present two simple signature-free blockchain consensus protocols for eventual synchrony with optimal good-case commit latency (three message delays for \(f<n/3\) and two for \(f<n/5\)), optimistic responsiveness, a block time of only two message delays without speculation, and \(O(n^2)\) communication per view. They instantiate Generic Simplex, a blockchain consensus construction parameterized by a new abstraction called view agreement. The same construction also captures Simplex, Minimmit, and a new synchronous signature-free protocol with optimal good-case commit latency of two message delays for \(f<n/4\).