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arxiv: 1906.12237 · v1 · pith:SXEIIUN7new · submitted 2019-06-28 · 💻 cs.CR

SybilQuorum: Open Distributed Ledgers Through Trust Networks

Alberto Sonnino , George Danezis This is my paper

Pith reviewed 2026-05-25 13:43 UTC · model grok-4.3

classification 💻 cs.CR
keywords Sybil attackdistributed ledgertrust networkFederated Byzantine Agreement Systemconsensusopen ledgersocial network defenseblockchain security
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The pith

Nodes expressing trust relationships through a ledger can bootstrap a value system and general transactions while thwarting Sybil attacks as a secure Federated Byzantine Agreement System.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper proposes that nodes in open distributed ledgers can record their trust relationships directly on the ledger. This recording allows the system to start and run both a value system and general transactions. Sybil attacks are prevented by drawing on social network defenses, and the overall setup functions as a secure Federated Byzantine Agreement System. The authors support this with an empirical evaluation and an extension of the underlying theory. A sympathetic reader would care because the method offers an alternative to resource-based defenses like proof of work or permissioned controls for peer-to-peer systems.

Core claim

Nodes expressing their trust relationships through the ledger can bootstrap and operate a value system and general transaction system while Sybil attacks are thwarted; the system is a secure Federated Byzantine Agreement System.

What carries the argument

SybilQuorum, a system in which trust relationships recorded on the ledger define quorums within an extended Federated Byzantine Agreement System to block Sybil attacks.

If this is right

  • An open value system can operate without proof-of-work, stake, or other resource commitments.
  • General transactions proceed among honest participants through the formed quorums.
  • Sybil attacks are blocked by the social-network structure of the expressed trusts.
  • The ledger functions as a complete transaction system once the trust network is established.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The same trust-recording approach could apply to other peer-to-peer systems that currently rely on resource proofs.
  • Deployment data would show how closely on-ledger trusts match offline social ties over time.
  • Energy consumption could drop relative to proof-of-work ledgers if the method scales.
  • Initial bootstrap might combine with existing social platforms to seed the first trust edges.

Load-bearing premise

Trust relationships expressed through the ledger reliably reflect real-world connections that cannot be gamed at scale by an attacker creating many fake nodes.

What would settle it

A simulation or deployment in which an attacker creates many fake nodes that form dense mutual trust links among themselves and then attempts to sway consensus outcomes or claim value.

Figures

Figures reproduced from arXiv: 1906.12237 by Alberto Sonnino, George Danezis.

Figure 1
Figure 1. Figure 1: Algorithms to determine safe set and quorum inters [PITH_FULL_IMAGE:figures/full_fig_p008_1.png] view at source ↗
read the original abstract

The Sybil attack plagues all peer-to-peer systems, and modern open distributed ledgers employ a number of tactics to prevent it from proof of work, or other resources such as space, stake or memory, to traditional admission control in permissioned settings. With SybilQuorum we propose an alternative approach to securing an open distributed ledger against Sybil attacks, and ensuring consensus amongst honest participants, leveraging social network based Sybil defences. We show how nodes expressing their trust relationships through the ledger can bootstrap and operate a value system, and general transaction system, and how Sybil attacks are thwarted. We empirically evaluate our system as a secure Federated Byzantine Agreement System, and extend the theory of those systems to do so.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 0 minor

Summary. The paper proposes SybilQuorum, an approach to securing open distributed ledgers against Sybil attacks by having nodes express trust relationships on the ledger. It claims this bootstraps and operates a value and transaction system while thwarting Sybils, leveraging social-network Sybil defenses. The system is evaluated empirically as a secure Federated Byzantine Agreement System (FBAS), with an extension to FBAS theory.

Significance. If the core security transfer from social-network properties to on-ledger trust graphs holds, the work would provide a resource-light alternative to PoW/stake for open ledgers and a concrete application of FBAS. The empirical evaluation and theoretical extension are noted strengths, but significance is constrained by the absence of any shown derivations or data supporting the key assumption that ledger-expressed trusts cannot be gamed at scale.

major comments (2)
  1. [Abstract] Abstract (paragraph on leveraging social network based Sybil defences): the claim that ledger-expressed trust relationships reliably encode real-world connections that thwart Sybil attacks at scale requires a derivation showing inheritance of expansion/conductance properties; none is supplied, so the FBAS safety guarantee does not transfer.
  2. [Abstract] Abstract: the empirical evaluation as a secure FBAS is asserted without any reported data, error bars, exclusion rules, or mechanism details, leaving the central security claim unsupported.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive comments on our manuscript. We respond to each major comment below.

read point-by-point responses

  1. Referee: [Abstract] Abstract (paragraph on leveraging social network based Sybil defences): the claim that ledger-expressed trust relationships reliably encode real-world connections that thwart Sybil attacks at scale requires a derivation showing inheritance of expansion/conductance properties; none is supplied, so the FBAS safety guarantee does not transfer.

    Authors: We agree that a formal derivation is required to rigorously establish that on-ledger trust expressions inherit the expansion or conductance properties from underlying social networks. The current manuscript presents an informal argument based on the premise that ledger-expressed trusts reflect real-world connections, but does not supply the requested mathematical derivation. We will add this derivation in the revised version. revision: yes

  2. Referee: [Abstract] Abstract: the empirical evaluation as a secure FBAS is asserted without any reported data, error bars, exclusion rules, or mechanism details, leaving the central security claim unsupported.

    Authors: The full manuscript contains the empirical evaluation and theoretical extension in the body text. However, the abstract itself does not report specific data, error bars, exclusion rules, or mechanism details. We will revise the abstract to reference key evaluation outcomes and ensure the main text explicitly includes error bars, exclusion criteria, and simulation parameters. revision: partial

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The paper presents a system that expresses trust relationships on-ledger to leverage external social-network Sybil defenses and extend FBAS theory, with an empirical evaluation. No equations, fitted parameters, or self-referential definitions appear in the abstract or described claims that would reduce any prediction or security guarantee to the inputs by construction. The bootstrap mechanism and consensus properties are framed as building on independent social-network properties rather than internally defined quantities. No load-bearing self-citations or ansatzes smuggled via prior author work are quoted that collapse the central result.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 1 invented entities

The central claim rests on the domain assumption that social-network Sybil defenses transfer to ledger-based consensus without additional mechanisms; no free parameters or invented physical entities are named.

axioms (1)
  • domain assumption Social network based Sybil defences can be leveraged to secure open distributed ledgers and ensure consensus
    Invoked in the abstract as the core alternative approach.
invented entities (1)
  • SybilQuorum system no independent evidence
    purpose: To bootstrap value and transaction systems on open ledgers using expressed trust relationships
    New named construction introduced to solve the Sybil problem in this setting.

pith-pipeline@v0.9.0 · 5641 in / 1265 out tokens · 20777 ms · 2026-05-25T13:43:51.710726+00:00 · methodology

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Reference graph

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