Solida: A Blockchain Protocol Based on Reconfigurable Byzantine Consensus

Abraham, Ittai; Malkhi, Dahlia; Nayak, Kartik; Liu, Ren; Spiegelman, Alexander

doi:10.48550/arxiv.1612.02916

Cited by 9 publications

(16 citation statements)

References 13 publications

(28 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another approach to improving blockchain-based money transfer protocols is to replace Nakamoto consensus with a more classical Byzantine fault tolerant consensus protocol such as PBFT [9]. These protocols [3,25] typically offer more classical safety and liveness guarantees than Nakamoto consensus, such as transaction finality. However, they still adopt the fault tolerance model that up to < 3 of agents may be Byzantine and that the rest are correct.…”

Section: Related Workmentioning

confidence: 99%

Who Needs Consensus? A Distributed Monetary System Between Rational Agents via Hearsay

Georghiades¹,

Streit²,

Garg³

2021

Preprint

View full text Add to dashboard Cite

We propose a novel distributed monetary system called Hearsay that tolerates both Byzantine and rational behavior without the need for agents to reach consensus on executed transactions. Recent work [5,10,15] has shown that distributed monetary systems do not require consensus and can operate using a broadcast primitive with weaker guarantees, such as reliable broadcast. However, these protocols assume that some number of agents may be Byzantine and the remaining agents are perfectly correct. For the application of a monetary system in which the agents are real people with economic interests, the assumption that agents are perfectly correct may be too strong. We expand upon this line of thought by weakening the assumption of correctness and instead adopting a fault tolerance model which allows up to < 3 agents to be Byzantine and the remaining agents to be rational. A rational agent is one which will deviate from the protocol if it is in their own best interest. Under this fault tolerance model, Hearsay implements a monetary system in which all rational agents achieve agreement on executed transactions. Moreover, Hearsay requires only a single broadcast per transaction. In order to incentivize rational agents to behave correctly in Hearsay, agents are rewarded with transaction fees for participation in the protocol and punished for noticeable deviations from the protocol. Additionally, Hearsay uses a novel broadcast primitive called Rational Reliable Broadcast to ensure that agents can broadcast messages under Hearsay's fault tolerance model. Rational Reliable Broadcast achieves equivalent guarantees to Byzantine Reliable Broadcast [7] but can tolerate the presence of rational agents. To show this, we prove that following the Rational Reliable Broadcast protocol constitutes a Nash equilibrium between rational agents. We deem Rational Reliable Broadcast to be a secondary contribution of this work which may be of independent interest.

show abstract

Section: Related Workmentioning

confidence: 99%

Who Needs Consensus? A Distributed Monetary System Between Rational Agents via Hearsay

Georghiades¹,

Streit²,

Garg³

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…that The nodes have to know the latest blocks to avoid forks (the same as BFT assumption) but do not set an upper bound of message delivery time (partial synchronous network assumption). The solutions include the dBFT of NEO, the BFT of Mir-BFT [35], the BFT of Hotstuff [36], the PoS+PBFT of Tendermint [37] [38], the vote-based BFT of Algorand [39], the Raft+PBFT of Tangaroa [40], the variant PBFT of Thunderella [41], PeerConsensus [42], ByzCoin [43], and Solida [44]. Several systems [45] even directly weaken the safety assumption of BFT consensus, by modifying a strictly ordered sequence into a partially ordered sequence.…”

Section: Q3how To Mitigate the Issue?mentioning

confidence: 99%

Security Analysis on dBFT Protocol of NEO

Wang

Peng

et al. 2020

Lecture Notes in Computer Science

View full text Add to dashboard Cite

NEO is one of the top public chains worldwide. We focus on its backbone consensus protocol, called delegated Byzantine Fault Tolerance (dBFT). The dBFT protocol has been adopted by a variety of blockchain systems such as ONT. dBFT claims to guarantee the security when no more than f = n 3 nodes are Byzantine, where n is the total number of consensus participants. However, we identify attacks to break the claimed security. In this paper, we show our results by providing a security analysis on its dBFT protocol. First, we evaluate NEO's source code and formally present the procedures of dBFT via the state machine replication (SMR) model. Next, we provide a theoretical analysis with two example attacks. These attacks break the security of dBFT with no more than f nodes. Then, we provide recommendations on how to fix the system against the identified attacks. The suggested fixes have been accepted by the NEO official team. Finally, we further discuss the reasons causing such issues, the relationship with current permissioned blockchain systems, and the scope of potential influence.

show abstract

“…These parameters encapsulate the effects of both fundamental network properties (e.g., hardware, topology), as well as resources consumed by the network's relaying mechanism, such as validity checking of transactions or blocks. 1 Assuming that each transaction needs to be communicated at least once across the network, it holds that λ, the number of transactions which can be confirmed per second, is at most C, i.e. λ < C.…”

Section: Physical Limitsmentioning

confidence: 99%

“…At the same time, Prism achieves a confirmation latency for honest transactions matching the two physical limits (2) and (3). In particular, if the desired security parameter log 1 ε ≪ CD/B v , the confirmation latency is of the order of the propagation delay and independent of log 1/ε. Put another way, one can achieve latency close to the propagation delay with a confirmation error probability exponentially small in the bandwidth-delay product CD/B v .…”

Section: 𝑂(𝐷)mentioning

confidence: 99%

“…Hybrid blockchain-BFT consensus. Several protocols combine ideas from Byzantine fault tolerant (BFT) based consensus into a PoW setting [1,13,20,21]. ByzCoin [13] and its predecessor Disc-Coin [6] attempt to address the latency shortcoming of BitcoinNG but is proven in a later paper [20] to be insecure when the adversarial fraction β > 0.25.…”

Section: Performance Of Existing Pow Protocolsmentioning

confidence: 99%

See 1 more Smart Citation

Deconstructing the Blockchain to Approach Physical Limits

Bagaria,

Kannan,

Tse

et al. 2018

Preprint

View full text Add to dashboard Cite

The concept of a blockchain was invented by Satoshi Nakamoto to maintain a distributed ledger. In addition to its security, important performance measures of a blockchain protocol are its transaction throughput and confirmation latency. In a decentralized setting, these measures are limited by two underlying physical network attributes: communication capacity and speed-of-light propagation delay. In this work we introduce Prism, a new proof-of-work blockchain protocol, which can achieve 1) security against up to 50% adversarial hashing power; 2) optimal throughput up to the capacity C of the network; 3) confirmation latency for honest transactions proportional to the propagation delay D, with confirmation error probability exponentially small in the bandwidth-delay product CD; 4) eventual total ordering of all transactions. Our approach to the design of this protocol is based on deconstructing Nakamoto's blockchain into its basic functionalities and systematically scaling up these functionalities to approach their physical limits.

show abstract

Solida: A Blockchain Protocol Based on Reconfigurable Byzantine Consensus

Cited by 9 publications

References 13 publications

Who Needs Consensus? A Distributed Monetary System Between Rational Agents via Hearsay

Who Needs Consensus? A Distributed Monetary System Between Rational Agents via Hearsay

Security Analysis on dBFT Protocol of NEO

Deconstructing the Blockchain to Approach Physical Limits

Contact Info

Product

Resources

About