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An Unconditionally Hiding and Long-Term Binding Post-Quantum Commitment Scheme

Cabarcas, Daniel ; Demirel, Denise ; Göpfert, Florian ; Lancrenon, Jean ; Wunderer, Thomas :
An Unconditionally Hiding and Long-Term Binding Post-Quantum Commitment Scheme.

[Report] , (2015)

Kurzbeschreibung (Abstract)

Commitment schemes are among cryptography's most important building blocks. Besides their basic properties, hidingness and bindingness, for many applications it is important that the schemes applied support proofs of knowledge. However, all existing solutions which have been proven to provide these protocols are only computationally hiding or are not resistant against quantum adversaries. This is not suitable for long-lived systems, such as long-term archives, where commitments have to provide security also in the long run. Thus, in this work we present a new post-quantum unconditionally hiding commitment scheme that supports (statistical) zero-knowledge protocols and allows to refreshes the binding property over time. The bindingness of our construction relies on the approximate shortest vector problem, a lattice problem which is conjectured to be hard for polynomial approximation factors, even for a quantum adversary. Furthermore, we provide a protocol that allows the committer to prolong the bindingness property of a given commitment while showing in zero-knowledge fashion that the value committed to did not change. In addition, our construction yields two more interesting features: one is the ability to "convert" a Pedersen commitment into a lattice-based one, and the other one is the construction of a hybrid approach whose bindingness relies on the discrete logarithm and approximate shortest vector problems.

Typ des Eintrags: Report
Erschienen: 2015
Autor(en): Cabarcas, Daniel ; Demirel, Denise ; Göpfert, Florian ; Lancrenon, Jean ; Wunderer, Thomas
Titel: An Unconditionally Hiding and Long-Term Binding Post-Quantum Commitment Scheme
Sprache: Englisch
Kurzbeschreibung (Abstract):

Commitment schemes are among cryptography's most important building blocks. Besides their basic properties, hidingness and bindingness, for many applications it is important that the schemes applied support proofs of knowledge. However, all existing solutions which have been proven to provide these protocols are only computationally hiding or are not resistant against quantum adversaries. This is not suitable for long-lived systems, such as long-term archives, where commitments have to provide security also in the long run. Thus, in this work we present a new post-quantum unconditionally hiding commitment scheme that supports (statistical) zero-knowledge protocols and allows to refreshes the binding property over time. The bindingness of our construction relies on the approximate shortest vector problem, a lattice problem which is conjectured to be hard for polynomial approximation factors, even for a quantum adversary. Furthermore, we provide a protocol that allows the committer to prolong the bindingness property of a given commitment while showing in zero-knowledge fashion that the value committed to did not change. In addition, our construction yields two more interesting features: one is the ability to "convert" a Pedersen commitment into a lattice-based one, and the other one is the construction of a hybrid approach whose bindingness relies on the discrete logarithm and approximate shortest vector problems.

Freie Schlagworte: Secure Data;Solutions;S6;PRISMACLOUD;P1;Primitives;unconditionally hiding commitments, post-quantum, lattice-based cryptography, long-term security, proof of knowledge
Fachbereich(e)/-gebiet(e): DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche > SFB 1119: CROSSING – Kryptographiebasierte Sicherheitslösungen als Grundlage für Vertrauen in heutigen und zukünftigen IT-Systemen
20 Fachbereich Informatik > Theoretische Informatik - Kryptographie und Computeralgebra
LOEWE > LOEWE-Zentren > CASED – Center for Advanced Security Research Darmstadt
20 Fachbereich Informatik > Theoretische Informatik - Kryptographie und Computeralgebra > LTSec - Langzeitsicherheit
Profilbereiche > Cybersicherheit (CYSEC)
20 Fachbereich Informatik > Theoretische Informatik - Kryptographie und Computeralgebra > Post-Quantum Kryptographie
LOEWE > LOEWE-Zentren
DFG-Sonderforschungsbereiche (inkl. Transregio) > Sonderforschungsbereiche
20 Fachbereich Informatik
Profilbereiche
LOEWE
DFG-Sonderforschungsbereiche (inkl. Transregio)
Hinterlegungsdatum: 15 Nov 2016 23:15
ID-Nummer: TUD-CS-2015-0141
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