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The secure parameters and efficient decryption algorithm for multivariate public key cryptosystem EFC

Journal Article


Abstract


  • At PQCrypto 2016, Szepieniec et al. proposed a new type of trapdoor called Extension Field Cancellation (EFC) for constructing secure multivariate encryption cryptosystems. They also specifically suggested two schemes EFC−p and EFC−pt2 that apply this trapdoor and some modifiers. Although both of them seem to avoid all attacks used for cryptanalysis on multivariate cryptography, their decryption efficiency has room for improvement. On the other hand, their security was analyzed mainly through an algebraic attack of computing the Gröbner basis of the public key, and there possibly exists more effective attacks. In this paper, we introduce a more efficient decryption approach for EFC−p and EFC−pt2, which manages to avoid all redundant computation involved in the original decryption algorithms without altering their public key. In addition, we estimate the secure parameters for EFC−p and EFC−pt2 through a hybrid attack of algebraic attack and exhaustive search.

UOW Authors


  •   Wang, Yacheng (external author)
  •   Ikematsu, Yasuhiko (external author)
  •   Duong, Dung Hoang.
  •   Takagi, Tsuyoshi (external author)

Publication Date


  • 2019

Citation


  • Wang, Y., Ikematsu, Y., Duong, D. Hoang. & Takagi, T. (2019). The secure parameters and efficient decryption algorithm for multivariate public key cryptosystem EFC. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, E102-A (9), 1028-1036.

Scopus Eid


  • 2-s2.0-85072680889

Number Of Pages


  • 8

Start Page


  • 1028

End Page


  • 1036

Volume


  • E102-A

Issue


  • 9

Place Of Publication


  • Japan

Abstract


  • At PQCrypto 2016, Szepieniec et al. proposed a new type of trapdoor called Extension Field Cancellation (EFC) for constructing secure multivariate encryption cryptosystems. They also specifically suggested two schemes EFC−p and EFC−pt2 that apply this trapdoor and some modifiers. Although both of them seem to avoid all attacks used for cryptanalysis on multivariate cryptography, their decryption efficiency has room for improvement. On the other hand, their security was analyzed mainly through an algebraic attack of computing the Gröbner basis of the public key, and there possibly exists more effective attacks. In this paper, we introduce a more efficient decryption approach for EFC−p and EFC−pt2, which manages to avoid all redundant computation involved in the original decryption algorithms without altering their public key. In addition, we estimate the secure parameters for EFC−p and EFC−pt2 through a hybrid attack of algebraic attack and exhaustive search.

UOW Authors


  •   Wang, Yacheng (external author)
  •   Ikematsu, Yasuhiko (external author)
  •   Duong, Dung Hoang.
  •   Takagi, Tsuyoshi (external author)

Publication Date


  • 2019

Citation


  • Wang, Y., Ikematsu, Y., Duong, D. Hoang. & Takagi, T. (2019). The secure parameters and efficient decryption algorithm for multivariate public key cryptosystem EFC. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, E102-A (9), 1028-1036.

Scopus Eid


  • 2-s2.0-85072680889

Number Of Pages


  • 8

Start Page


  • 1028

End Page


  • 1036

Volume


  • E102-A

Issue


  • 9

Place Of Publication


  • Japan