QuickSync: A Quickly Synchronizing PoS-Based Blockchain Protocol

by   Shoeb Siddiqui, et al.

To implement a blockchain, we need a blockchain protocol for all the nodes to follow. To design a blockchain protocol, we need a block publisher selection mechanism and a chain selection rule. In Proof-of-Stake (PoS) based blockchain protocols, block publisher selection mechanism selects the node to publish the next block based on the relative stake held by the node. However, PoS protocols, such as Ouroboros v1, may face vulnerability to fully adaptive corruptions. In this paper, we propose a novel PoS-based blockchain protocol, QuickSync, to achieve security against fully adaptive corruptions while improving on performance. We propose a metric called block power, a value defined for each block, derived from the output of the verifiable random function based on the digital signature of the block publisher. With this metric, we compute chain power, the sum of block powers of all the blocks comprising the chain, for all the valid chains. These metrics are a function of the block publisher's stake to enable the PoS aspect of the protocol. The chain selection rule selects the chain with the highest chain power as the one to extend. This chain selection rule hence determines the selected block publisher of the previous block. When we use metrics to define the chain selection rule, it may lead to vulnerabilities against Sybil attacks. QuickSync uses a Sybil attack resistant function implemented using histogram matching. We prove that QuickSync satisfies common prefix, chain growth, and chain quality properties and hence it is secure. We also show that it is resilient to different types of adversarial attack strategies. Our analysis demonstrates that QuickSync performs better than Bitcoin by an order of magnitude on both transactions per second and time to finality, and better than Ouroboros v1 by a factor of three on time to finality.


page 1

page 2

page 3

page 4


Radium: Improving Dynamic PoW Targeting

Most PoW blockchain protocols operate with a simple mechanism whereby a ...

Efficient and Secure TSA for the Tangle

The Tangle is the data structure used to store transactions in the IOTA ...

Fast-HotStuff: A Fast and Resilient HotStuff Protocol

The HotStuff protocol is a recent breakthrough inByzantine Fault Toleran...

Securing Parallel-chain Protocols under Variable Mining Power

Several emerging PoW blockchain protocols rely on a "parallel-chain" arc...

Parasite Chain Detection in the IOTA Protocol

In recent years several distributed ledger technologies based on directe...

Blockchain mechanism and distributional characteristics of cryptos

We investigate the relationship between underlying blockchain mechanism ...

Security of Blockchains at Capacity

Given a network of nodes with certain communication and computation capa...

Please sign up or login with your details

Forgot password? Click here to reset