Abstract
Recent research within the field of cryptography has suggested that S-boxes should be chosen to contain few fixed points, motivating analysis of the fixed points of permutations. This paper presents a novel mean of obtaining fixed points for all functions satisfying a property put forth by Carlitz. We determine particular results concerning the fixed points of rational functions. Such concepts allow the derivation of an algorithm which cyclically generates fixed points for all three classes of functions satisfying the Carlitz property, the most renowned of which are Rédei rational functions. Specifically, we present all fixed points for any given Rédei function in a single cycle, generated by a particular non-constant rational transformation. For the other two classes of functions, we present their fixed points in cycles consisting of smaller cycles of fixed points. Finally, we provide an explicit expression for the fixed points of all Rédei functions over \({\mathbb {F}}_q\).

Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.References
Barbero, S., Cerruti, U., Murru, N.: Solving the Pell equation via Rédei rational functions. Fibonacci Q. 48(4), 348–357 (2010)
Bellini, E., Murru, N.: An efficient and secure RSA-like cryptosystem exploiting Rédei rational functions over conics. Finite Fields Appl. 39, 179–194 (2016)
Carlitz, L.: A note on permutation functions over a finite field. Duke Math. J. 29(2), 325–332 (1962)
Cesmelioglu, A., Meidl, W., Topuzoglu, A.: On the cycle structure of permutation polynomials. Finite Fields Appl. 14(3), 593–614 (2008)
Charpin, P., Mesnager, S., Sarkar, S.: Dickson polynomials that are involutions. In: Canteaut, A., Effinger, G., Huczynska, S., Panario, D., Storme, L. (eds.) Contemporary Developments in Finite Fields and Applications, pp. 22–47. World Scientific Publishing, Singapore (2016)
Charpin, P., Mesnager, S., Sarkar, S.: Involutions over the Galois field \({\mathbb{F}}_{2^n}\). IEEE Trans. Inf. Theory 62(4), 2266–2276 (2016)
Chubb, K.: Fixed Points of Rational Functions Satisfying the Carlitz Property. M.Sc. Thesis, Carleton University (2018)
Gutierrez, J., Winterhof, A.: Exponential sums of non-linear congruential pseudorandom number generators with Rédei functions. Finite Fields Appl. 14(2), 410–416 (2008)
Kameswari, P.A., Kumari, R.C.: Cryptosystem with Rédei rational functions via Pell conics. Int. J. Comput. Appl. 54(15), 1–6 (2012)
Lidl, R., Niederreiter, H.: Finite Fields, 2nd edn. Cambridge University Press, Cambridge (1997)
Nobauer, R.: Cryptanalysis of the Rédei scheme. Contributions to General Algebra, vol. 3, pp. 255–264. Teubner, Vienna (1984)
Panario, D., Sadeghi, M., Sakzad, A.: Cycle structure of permutation functions over finite fields and their applications. Adv. Math. Commun. 6(3), 347–361 (2012)
Qureshi, C., Panario, D.: Rédei actions on finite fields and multiplication map in cyclic group. SIAM J. Discrete Math. 29(3), 1486–1503 (2015)
Rubio, I., Pacheco-Tallaj, N., Corrada-Bravo, C., Castro, F.: Explicit formulas for monomial involutions over finite fields. Adv. Math. Commun. 11(2), 301–306 (2017)
Wang, Q.: A note on inverses of cyclotomic mapping permutation polynomials over finite fields. Finite Fields Appl. 45, 422–427 (2017)
Wu, B., Liu, Z.: Linearized polynomials over finite fields revisited. Finite Fields Appl. 22, 79–100 (2013)
Youssef, A., Tavares, S., Heys, H.: A new class of substitution-permutation networks. In: Proceedings of Selected Areas in Cryptography, SAC-96, pp. 132–147 (1996)
Acknowledgements
This work served as partial fulfillment of the requirements for a Master of Science in Mathematics by the first author [7], and was conducted under the supervision of the latter two authors. The second and third authors are partially funded by NSERC of Canada. We also thank the anonymous referees for their helpful suggestions.
Author information
Authors and Affiliations
Corresponding author
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Appendices
Appendices
Let \(q=p^t\), \(a \in {\mathbb {F}}_q\), and \(\Phi \in {\mathbb {F}}_{q^2}\), with \(a = \Phi ^2\). Algorithms for producing all of the fixed points in \({\mathbb {F}}_q\) for functions f satisfying the Carlitz property are given in [7]. In the following, we give sample outputs from these algorithms.
1.1 A: Sample fixed points for Type-1 functions
See Table 1.
1.2 B: Sample fixed points for Rédei functions
1.3 C: Sample fixed points for Type-3 functions
See Table 4.
Rights and permissions
About this article
Cite this article
Chubb, K., Panario, D. & Wang, Q. Fixed points of rational functions satisfying the Carlitz property. AAECC 30, 417–439 (2019). https://doi.org/10.1007/s00200-019-00382-2
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00200-019-00382-2