Highway: Efficient Consensus with Flexible Finality

by   Daniel Kane, et al.

There has been recently a lot of progress in designing efficient partially synchronous BFT consensus protocols that are meant to serve as core consensus engines for Proof of Stake blockchain systems. While the state-of-the-art solutions attain virtually optimal performance under this theoretical model, there is still room for improvement, as several practical aspects of such systems are not captured by this model. Most notably, during regular execution, due to financial incentives in such systems, one expects an overwhelming fraction of nodes to honestly follow the protocol rules and only few of them to be faulty, most likely due to temporary network issues. Intuitively, the fact that almost all nodes behave honestly should result in stronger confidence in blocks finalized in such periods, however it is not the case under the classical model, where finality is binary. We propose Highway, a new consensus protocol that is safe and live in the classical partially synchronous BFT model, while at the same time offering practical improvements over existing solutions. Specifically, block finality in Highway is not binary but is expressed by fraction of nodes that would need to break the protocol rules in order for a block to be reverted. During periods of honest participation finality of blocks might reach well beyond 1/3 (as what would be the maximum for classical protocols), up to even 1 (complete certainty). Having finality defined this way, Highway offers flexibility with respect to the configuration of security thresholds among nodes running the protocol, allowing nodes with lower thresholds to reach finality faster than the ones requiring higher levels of confidence.


page 1

page 2

page 3

page 4


Carnot: A highly Scalable and Responsive BFT Consensus protocol

We present Carnot, a leader-based Byzantine Fault Tolerant (BFT) consens...

Fast B4B: Fast BFT for Blockchains

Low latency is one of the desired properties for partially synchronous B...

PoSAT: Proof-of-Work Availability andUnpredictability, without the Work

An important feature of Proof-of-Work (PoW) blockchains is full dynamic ...

Blockmania: from Block DAGs to Consensus

Blockmania is a byzantine consensus protocol. Nodes emit blocks forming ...

A General Framework for the Security Analysis of Blockchain Protocols

Blockchain protocols differ in fundamental ways, including the mechanics...

Recent Latest Message Driven GHOST: Balancing Dynamic Availability With Asynchrony Resilience

Dynamic participation has recently become a key requirement to devise pe...

Improving Asynchrony Resilience in Dynamically Available Total-Order Broadcast Protocols

Dynamically available total-order broadcast (TOB) protocols are essentia...

Please sign up or login with your details

Forgot password? Click here to reset