Smith-Tone, D.
(2019),
Practical Cryptanalysis of k-ary C*, Cryptology ePrint Archive, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=928519, https://eprint.iacr.org/2019/841
(Accessed April 25, 2024)
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
Practical Cryptanalysis of k-ary C*
Published
Author(s)
Abstract
Recently, an article by Felke appeared in Cryptography and Communications discussing the security of biquadratic $C^*$ and a further generalization, k-ary $C^*$. The article derives lower bounds for the complexity of an algebraic attack, directly inverting the public key, under an assumption that the first-fall degree is a good approximation of the solving degree, an assumption that the paper notes requires ``greater justification and clarification.'' In this work, we provide a practical attack breaking all k-ary $C^*$ schemes. The attack is based on differential techniques and requires nothing but the ability to evaluate the public key and solve linear systems. In particular, the attack breaks the parameters provided in CryptoChallenge 11 by constructing and solving linear systems of moderate size in a few minutes.Citation
Cryptology ePrint Archive
Volume
2019
Pub Weblink
Pub Type
Websites
Download Paper
Keywords
Multivariate Cryptography, k-ary C*, differential attack
Citation
Created July 18, 2019, Updated July 29, 2019