Cryptanalysis of the DECT Standard Cipher
- 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.