Paper 2004/010

Fast Pseudo-Hadamard Transforms

Tom St Denis


We prove that the fast pseudo-Hadamard transform (FPHT) over a finite field has a bounded branch number. We shall demonstrate that the transform has an efficient implementation for various platforms compared to an equal dimension MDS code. We prove that when using a CS-Cipher\cite{CSC} like construction the weight of any $2R$ trail is bounded for the case of an $8 \times 8$ transform. We show that the FPHT can also be combined with MDS codes to produce efficient transforms with half of the branch of a comparable sized MDS code. We present the FPHT-HASH one-way hash function which is constructed using a $32 \times 32$ FPHT which produces a $256$-bit digest and processes the input at 24 cycles per byte with ISO C source code on an AMD Athlon XP processor.

Note: Minor typographical errors fixed.

Available format(s)
Secret-key cryptography
Publication info
Published elsewhere. Unknown where it was published
Pseudo-Hadamard TransformBranch AnalysisOne-Way Hash Function
Contact author(s)
tomstdenis @ iahu ca
2004-02-02: last of 3 revisions
2004-01-21: received
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      author = {Tom St Denis},
      title = {Fast Pseudo-Hadamard Transforms},
      howpublished = {Cryptology ePrint Archive, Paper 2004/010},
      year = {2004},
      note = {\url{}},
      url = {}
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