Projects per year
Abstract
We describe a digital signature scheme, whose security relies on the conjectured hardness of the Polynomial Learning With Errors problem for at least one defining polynomial within an exponential-size family (as a function of the security parameter). The proposed signature scheme follows the Fiat-Shamir framework and can be viewed as the Learning With Errors counterpart of the signature scheme described by Lyubashevsky at Asiacrypt 2016, whose security relies on the conjectured hardness of the Polynomial Short Integer Solution problem for at least one defining polynomial within an exponential-size family. As opposed to the latter, enjoys a security proof from that is tight in the quantum-access random oracle model. The main ingredient is a reduction from for an arbitrary defining polynomial among exponentially many, to a variant of the Middle-Product Learning with Errors problem that allows for secrets that are small compared to the working modulus. We present concrete parameters for using such small secrets, and show that they lead to significant savings in signature length over Lyubashevsky’s Asiacrypt 2016 scheme (which uses larger secrets) at typical security levels. As an additional small contribution, and in contrast to (or), we present an efficient key-recovery attack against Lyubashevsky’s scheme (or the inhomogeneous problem), when it is used with sufficiently small secrets, showing the necessity of a lower bound on secret size for the security of that scheme.
Original language | English |
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Title of host publication | Public-Key Cryptography – PKC 2020 |
Subtitle of host publication | 23rd IACR International Conference on Practice and Theory of Public-Key Cryptography Edinburgh, UK, May 4–7, 2020 Proceedings, Part II |
Editors | Aggelos Kiayias, Markulf Kohlweiss, Petros Wallden, Vassilis Zikas |
Place of Publication | Cham Switzerland |
Publisher | Springer |
Pages | 66-93 |
Number of pages | 28 |
ISBN (Electronic) | 9783030453886 |
ISBN (Print) | 9783030453879 |
DOIs | |
Publication status | Published - 2020 |
Event | International Conference/Workshop on Practice and Theory in Public Key Cryptography 2020 - Online Duration: 1 Jun 2020 → 4 Jun 2020 Conference number: 23rd https://link.springer.com/book/10.1007/978-3-030-45388-6 (Proceedings) https://pkc.iacr.org/2020/ (Website) |
Publication series
Name | Lecture Notes in Computer Science |
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Publisher | Springer |
Volume | 12111 |
ISSN (Print) | 0302-9743 |
ISSN (Electronic) | 1611-3349 |
Conference
Conference | International Conference/Workshop on Practice and Theory in Public Key Cryptography 2020 |
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Abbreviated title | PKC 2020 |
Period | 1/06/20 → 4/06/20 |
Internet address |
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Projects
- 1 Finished
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Privacy-preserving Data Processing on the Cloud
Steinfeld, R., Pieprzyk, J. P., Liu, J., Desmedt, Y. & Wang, H.
20/06/18 → 30/06/24
Project: Research