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RAMus- A New Lightweight Block Cipher for RAM Encryption

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Security and Cryptography for Networks (SCN 2022)

Part of the book series: Lecture Notes in Computer Science ((LNCS,volume 13409))

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Abstract

Over the past decades, there has been a dramatic increase of the attacks recovering the data from the RAM memory. These have heightened the need for new solutions and primitives suitable for the encryption of this information. In this paper we introduce RAMus, a new tweakable lightweight block cipher whose properties support its usage for securing the RAM memory. In this sense, RAMus attains all the requirements provided by the (German) Federal Office of Information Security (BSI) in the domain of encryption algorithms suitable for RAM and memory encryption. The design strategy of RAMus is inspired from the LS-approach. Compared to the literature, in our proposal the linear layer is replaced by a second Sbox layer. In RAMus, the diffusion is ensured by the Sbox layers, which use Sboxes with a non-trivial branch number.

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Author information

Authors and Affiliations

  1. imec-COSIC, Department of Electrical Engineering (ESAT), KU Leuven, Leuven, Belgium

    Raluca Posteuca & Vincent Rijmen

  2. Department of Informatics, University of Bergen, 5020, Bergen, Norway

    Vincent Rijmen

Authors
  1. Raluca Posteuca
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  2. Vincent Rijmen
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Corresponding author

Correspondence to Raluca Posteuca .

Editor information

Editors and Affiliations

  1. Università degli Studi di Salerno, Fisciano, Italy

    Clemente Galdi

  2. University of California at Irvine, Irvine, CA, USA

    Stanislaw Jarecki

Appendices

Appendix 1. The Byte Description of the Sbox S

Table 4. The Sbox S. The output associated to the hexadecimal input xy can be depicted from the intersection of the row x0 and the column 0y. For example, \(S(c2) = 5d\).
Full size table

Appendix 2. The Integral Distinguisher Described in Sect. 6.3

We recall that, for this distinguisher, the first row is “active”, with the additional constraint that the tweak is equal to the plaintext.

Fig. 9.
figure 9

The 3-round integral distinguisher described in Sect. 6.3.

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Posteuca, R., Rijmen, V. (2022). RAMus- A New Lightweight Block Cipher for RAM Encryption. In: Galdi, C., Jarecki, S. (eds) Security and Cryptography for Networks. SCN 2022. Lecture Notes in Computer Science, vol 13409. Springer, Cham. https://doi.org/10.1007/978-3-031-14791-3_4

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  • DOI: https://doi.org/10.1007/978-3-031-14791-3_4

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