Cryptanalysis of the DECT Standard Cipher

  • Karsten Nohl
  • Erik Tews
  • Ralf-Philipp Weinmann
Conference paper

DOI: 10.1007/978-3-642-13858-4_1

Part of the Lecture Notes in Computer Science book series (LNCS, volume 6147)
Cite this paper as:
Nohl K., Tews E., Weinmann RP. (2010) Cryptanalysis of the DECT Standard Cipher. In: Hong S., Iwata T. (eds) Fast Software Encryption. FSE 2010. Lecture Notes in Computer Science, vol 6147. Springer, Berlin, Heidelberg


The DECT Standard Cipher (DSC) is a proprietary 64-bit stream cipher based on irregularly clocked LFSRs and a non-linear output combiner. The cipher is meant to provide confidentiality for cordless telephony. This paper illustrates how the DSC was reverse-engineered from a hardware implementation using custom firmware and information on the structure of the cipher gathered from a patent. Beyond disclosing the DSC, the paper proposes a practical attack against DSC that recovers the secret key from 215 keystreams on a standard PC with a success rate of 50% within hours; somewhat faster when a CUDA graphics adapter is available.


DECT DECT Standard Cipher stream cipher cryptanalysis linear feedback shift register 

Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Karsten Nohl
    • 1
  • Erik Tews
    • 2
  • Ralf-Philipp Weinmann
    • 3
  1. 1.University of Virginia 
  2. 2.Technische Universität Darmstadt 
  3. 3.University of Luxembourg 

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