an:06043984
Zbl 1292.94096
Krause, Matthias; Hamann, Matthias
The cryptographic power of random selection
EN
Miri, Ali (ed.) et al., Selected areas in cryptography. 18th international workshop, SAC 2011, Toronto, ON, Canada, August 11--12, 2011. Revised selected papers. Berlin: Springer (ISBN 978-3-642-28495-3/pbk). Lecture Notes in Computer Science 7118, 134-150 (2012).
2012
a
94A60
Lightweight Cryptography; Algebraic Attacks; Algorithmic Learning; Foundations and Complexity Theory
Summary: The principle of random selection and the principle of adding biased noise are new paradigms used in several recent papers for constructing lightweight RFID authentication protocols. The cryptographic power of adding biased noise can be characterized by the hardness of the intensively studied Learning Parity with Noise (LPN) Problem. In analogy to this, we identify a corresponding learning problem for random selection and study its complexity. Given \(L\) secret linear functions \(f_1,\ldots,f_L:\{0,1\}^n\longrightarrow\{0,1\}^a\), \(RandomSelect\left(L,n,a\right)\) denotes the problem of learning \(f _{1},\cdots ,f _{L }\) from values \(\left(u,f_l\left(u\right)\right)\), where the secret indices \(l \in \{1,\cdots ,L\}\) and the inputs \(u\in\{0,1\}^n\) are randomly chosen by an oracle. We take an algebraic attack approach to design a nontrivial learning algorithm for this problem, where the running time is dominated by the time needed to solve full-rank systems of linear equations over \(O\left(n^L\right)\) unknowns. In addition to the mathematical findings relating correctness and average running time of the suggested algorithm, we also provide an experimental assessment of our results.
For the entire collection see [Zbl 1234.94005].