Decentralizing Permissioned Blockchain with Delay Towers

TL;DR

This paper introduces L4L, a novel approach using delay towers with verifiable delay functions to decentralize permissioned blockchains like Libra, achieving high scalability and low environmental impact without extensive token incentives.

Contribution

L4L is the first to apply delay towers for decentralization in permissioned blockchains, offering an eco-friendly, scalable, and permissionless alternative to traditional consensus mechanisms.

Findings

Decentralization cost is nearly negligible.

Delay towers are effective without token pre-sales.

Method promotes compliance and sustainability.

Abstract

Growing excitement around permissionless blockchains is uncovering its latent scalability concerns. Permissioned blockchains offer high transactional throughput and low latencies while compromising decentralization. In the quest for a decentralized, scalable blockchain fabric, i.e., to offer the scalability of permissioned blockchain in a permissionless setting, we present L4L to encourage decentralization over the permissioned Libra network without compromising its sustainability. L4L employs delay towers, -- puzzle towers that leverage verifiable delay functions -- for establishing identity in a permissionless setting. Delay towers cannot be parallelized due to their sequential execution, making them an eco-friendly alternative. We also discuss methodologies to replace validators participating in consensus to promote compliant behavior. Our evaluations found that the cost of enabling decentralization over permissioned networks is almost negligible. Furthermore, delay towers offer an alternative to existing permissionless consensus mechanisms without requiring airdrops or pre-sale of tokens.