Karim Eldefrawy

Cryptography, Cybersecurity, Privacy

Co-founder and CTO at Confidencial.io
2017-2021: SRI
2011-2016: HRL Laboratories
2006-2010: PhD@UC Irvine

Scientific curiosity

Scientific knowledge map · Paper #26

Founding Digital Currency on Secure Computation

Karim Eldefrawy and Joshua Lampkins

2014 · ACM Conference on Computer and Communications Security (CCS)

  • Theory
  • protocol

What does the paper try to establish?

Can a digital currency combine centralized-style accountability with transaction and identity privacy while preserving a growing ledger against mobile long-term compromise?

What is the proposed answer?

The source abstract reports a privacy-preserving, proactively secure secret-shared ledger and transaction protocols, with techniques intended to reduce storage and proactive-refresh costs as the ledger grows; the manuscript body was not retrievable in this audit, so its exact parties, games, thresholds, constructions, and proofs remain pending.

Abstract

Most current digital currency schemes and associated ledgers are either centralized or completely distributed similar to the design adopted by Bitcoin. Centralized schemes enable accountability, but leave the privacy of users' identities and transactions in the hands of one organization. Distributed schemes can ensure better privacy but provide little accountability. In this paper we design a privacy-preserving proactively-secure distributed ledger and associated transaction protocols that can be used to implement an accountable digital currency that inherits the ledger's privacy and security features. One of the main technical challenges that we address is dealing with the increase in ledger size over time, an unavoidable aspect as the currency spreads and the ledger is required to be maintained for a long time in the future. We accomplish this by reducing the distributed (secret-shared) storage footprint and the required bandwidth and computation for proactively refreshing the ledger to ensure long-term confidentiality and security.

Provenance: Transcribed from the public author-uploaded full text; only typography, discretionary hyphenation, and line-break artifacts were normalized. Local file fixity has not been recorded.

Six dimensions, kept separate

The chart summarizes documented evidence and process. It is not a correctness probability, confidence score, or ranking, and no composite score is calculated.

The visual spider chart requires JavaScript. The complete values and rationales follow in text.

LowMediumHighN/A = not assessed

A smaller value means less documented support for that dimension, not that the paper is false or unimportant.

Epistemic evidence Low

The complete source abstract identifies the construction and intended efficiency gains, but exact models, protocols, proofs, and evidence were not body-audited.

Complete author-uploaded source abstract
Auditability High

A public author-uploaded full-text route exists, satisfying the site's author-copy rule; direct body retrieval and local fixity were not achieved in this audit.

Complete author-uploaded source abstract
Production provenance Medium

Named authorship, an author-uploaded route, and an ACM record establish baseline provenance; roles, revisions, and artifact lineage are unknown.

Complete author-uploaded source abstract Official ACM publication record
External scrutiny Medium

The paper has an ACM CCS publication record, but reviews and independent validation were not inspected.

Official ACM publication record
Reception High

OpenAlex reports 24 located citations as of 2026-07-11, meeting the site's 11+ high threshold. The index-specific count does not itself establish correctness or adoption.

Dated OpenAlex citation snapshot
Contribution significance Medium

The abstract presents a substantive privacy/accountability ledger construction, but theorem strength, priority, and impact were not independently source-audited.

Complete author-uploaded source abstract

Assessment: Ai draft author review pending · 2026-07-11 · rubric 0.2. These dimensions describe documented support and process, not truth, correctness, or a universal ranking. No composite score is calculated.

Hierarchical knowledge map

Collapse a branch for a top-level reading, or follow its source links and child nodes to audit the evidence and boundaries underneath it.

paper

Founding Digital Currency on Secure Computation

An abstract-grounded design for an accountable digital currency whose ledger remains secret-shared and proactively refreshed.

Complete author-uploaded source abstract
  1. question

    Research question

    research question from abstract

    Can ledger confidentiality and user privacy coexist with enforceable accountability and long-lived proactive security?

    Complete author-uploaded source abstract
  2. contribution

    Central answer

    source abstract asserted

    Maintain the ledger through distributed secret sharing and secure computation, attach privacy-preserving transaction protocols, and optimize storage and refresh as the ledger expands.

    Complete author-uploaded source abstract
  3. scope Privacy-accountability design space abstract level

    The abstract positions the design between one accountable but privacy-concentrating organization and a fully distributed system with less accountability.

    Complete author-uploaded source abstract
    1. threat model

      Long-term mobile compromise

      incompletely specified

      Proactive refresh implies security against changing corruptions over time, but the abstract does not state server count, corruption threshold, synchrony, erasures, authorization, or accountability trigger.

      Complete author-uploaded source abstract
  4. method

    Secret-shared ledger and transaction protocols

    source abstract asserted

    Ledger state is distributed in secret-shared form and processed through secure protocols, while storage footprint and periodic refresh cost are reduced for long-term growth.

    Complete author-uploaded source abstract
  5. claim group

    Abstract-level claims

    abstract only

    The source claims privacy-preserving proactive security, accountability, and lower distributed storage, bandwidth, and computation for refresh; no exact bounds are visible in the abstract.

    Complete author-uploaded source abstract
  6. limitation group

    Unverified boundaries

    material source gap

    The map cannot yet specify who can de-anonymize or regulate transactions, how double spending and consistency are handled, what mobile-adversary threshold holds, or which complexity improvements are proved.

    Complete author-uploaded source abstract
  7. scrutiny

    External scrutiny

    publication recorded

    The paper was published at ACM CCS 2014; reviews, proof audits, and later evaluations were not inspected.

    Official ACM publication record
  8. lineage

    Research direction

    source abstract asserted

    The design applies proactive MPC and secret-sharing techniques to a semi-centralized accountable-currency ledger.

    Complete author-uploaded source abstract

Source index

Locators state the depth of the current audit. PDF page numbers, where present, are one-based file pages; metadata-, summary-, and abstract-bounded records explicitly identify their limitations.

  1. Complete author-uploaded source abstract Abstract transcribed from author-uploaded PDF; body not audited
  2. Official ACM publication record CCS 2014, pages 1-14
  3. Dated OpenAlex citation snapshot cited_by_count = 24, accessed 2026-07-11