Skip to main content

On the Affine Transformations of HFE-Cryptosystems and Systems with Branches

  • Conference paper
Coding and Cryptography (WCC 2005)

Part of the book series: Lecture Notes in Computer Science ((LNSC,volume 3969))

Included in the following conference series:

Abstract

We show how to recover the affine parts of the secret key for a certain class of HFE-Cryptosystems. Further we will show that any system with branches can be decomposed in its single branches in polynomial time on average. The attack on the affine parts generalizes the results from [1, 11] to a bigger class of systems and is achieved by a different approach. Despite the fact that systems with branches are not used anymore (see [11, 6]), our second attack is a still of interest, as it shows that branches belong to the list of algebraic properties, which cannot be hidden by composition with secret affine transformations. We derived both algorithms by considering the cryptosystem as objects from the theory of nonassociative algebras and applying classical techniques from this theory. This general framework might be a useful tool for future investigations of HFE-Cryptosystems, e.g. to detect further invariants, which are not hidden by composition with affine transformations.

This is a preview of subscription content, log in via an institution to check access.

Access this chapter

Chapter
USD 29.95
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
eBook
USD 39.99
Price excludes VAT (USA)
  • Available as PDF
  • Read on any device
  • Instant download
  • Own it forever
Softcover Book
USD 54.99
Price excludes VAT (USA)
  • Compact, lightweight edition
  • Dispatched in 3 to 5 business days
  • Free shipping worldwide - see info

Tax calculation will be finalised at checkout

Purchases are for personal use only

Institutional subscriptions

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Beth, T., Geiselmann, W., Steinwandt, R.: Revealing 441 Key Bits of SFLASHv2. In: Nessie Workshop Munich (November 2002)

    Google Scholar 

  2. Patarin, J., Courtois, N.T., Goubin, L.: QUARTZ, 128-bit long digital signatures. In: Naccache, D. (ed.) CT-RSA 2001. LNCS, vol. 2020, pp. 282–297. Springer, Heidelberg (2001)

    Chapter  Google Scholar 

  3. Courtois, N., Goubin, L., Patarin, J.: SFLASHv3 a fast symmetric signature scheme. Cryptology ePrint Archive: Report 2003/211 (2003)

    Google Scholar 

  4. Dobbertin, H.: internal report 93/94, German Information Security Agency

    Google Scholar 

  5. Dobbertin, H.: Analysis of HFE Schemes Based on Power Functions. In: Invited talk at YACC 2002, June 03-07 (2002)

    Google Scholar 

  6. Patarin, J., Goubin, L., Courtois, N.T.: Improved Algorithms for Isomorphisms of Polynomials. In: Nyberg, K. (ed.) EUROCRYPT 1998. LNCS, vol. 1403, pp. 184–200. Springer, Heidelberg (1998)

    Chapter  Google Scholar 

  7. Imai, H., Matsumoto, T.: Public Quadratic Polynomial-tuples for efficient signature-verification and message-encryption. In: McCurley, K.S., Ziegler, C.D. (eds.) Advances in Cryptology 1981 - 1997. LNCS, vol. 1440, pp. 419–453. Springer, Heidelberg (1999)

    Google Scholar 

  8. Kipnis, A., Shamir, A.: Cryptanalysis of the HFE Public Key Cryptosystem by Relinearization. In: Wiener, M. (ed.) CRYPTO 1999. LNCS, vol. 1666, pp. 19–30. Springer, Heidelberg (1999)

    Chapter  Google Scholar 

  9. Kipnis, A., Shamir, A.: Cryptanalysis of the Oil & Vinegar Signature Scheme. In: Krawczyk, H. (ed.) CRYPTO 1998. LNCS, vol. 1462, pp. 206–222. Springer, Heidelberg (1998)

    Google Scholar 

  10. Lidl, R., Niederreiter, H.: Finite Fields, 2nd edn. Encyclopedia of Mathematics and its Applications, vol. 20. Cambridge University Press, Cambridge (1997)

    MATH  Google Scholar 

  11. Patarin, J.: Cryptanalysis of the Matsumoto and Imai Public Key Scheme of Eurocrypt 1988. In: McCurley, K.S., Ziegler, C.D. (eds.) Advances in Cryptology 1981 - 1997. LNCS, vol. 1440, pp. 248–261. Springer, Heidelberg (1999)

    Google Scholar 

  12. Patarin, J.: Asymmetric Cryptography with a Hidden Monomial. In: McCurley, K.S., Ziegler, C.D. (eds.) Advances in Cryptology 1981 - 1997. LNCS, vol. 1440, pp. 45–60. Springer, Heidelberg (1999)

    Google Scholar 

  13. Patarin, J.: Hidden Fields Equations (HFE) and Isomorphisms of Polynomials(IP): Two new families of Asymmetric Algorithms. In: McCurley, K.S., Ziegler, C.D. (eds.) Advances in Cryptology 1981 - 1997. LNCS, vol. 1440, pp. 33–48. Springer, Heidelberg (1999)

    Google Scholar 

  14. Schafer, R.: Introduction to Nonassociative Algebras. Academic Press, London (1966)

    MATH  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Editor information

Editors and Affiliations

Rights and permissions

Reprints and permissions

Copyright information

© 2006 Springer-Verlag Berlin Heidelberg

About this paper

Cite this paper

Felke, P. (2006). On the Affine Transformations of HFE-Cryptosystems and Systems with Branches. In: Ytrehus, Ø. (eds) Coding and Cryptography. WCC 2005. Lecture Notes in Computer Science, vol 3969. Springer, Berlin, Heidelberg. https://doi.org/10.1007/11779360_19

Download citation

  • DOI: https://doi.org/10.1007/11779360_19

  • Publisher Name: Springer, Berlin, Heidelberg

  • Print ISBN: 978-3-540-35481-9

  • Online ISBN: 978-3-540-35482-6

  • eBook Packages: Computer ScienceComputer Science (R0)

Publish with us

Policies and ethics