Talk:Lucifer (cipher)

Latest comment: 13 years ago by Lauri.pirttiaho in topic On Feistel's 1973 SciAm paper

On Feistel's 1973 SciAm paper

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In the article published in Scientific American, May 1973, the key size of the full implementation of Lucifer is not described. One described implementation is 128-bit block cipher utilizing SP-network with keyed S-boxes, two boxes per a set of 4 bits and one bit of key choosing the box to be used. P-boxes are 64 or 128 bits wide. It is not described in the article, how the key is divided into bits controlling the S-boxes, nor is it told, how many layers there are in the Lucifer. In the figures, system of 5 layers of S-boxes and 4 or 6 layers of P-boxes are shown. Also, in a figure the key is directly used, bit-by-bit and layer-by-layer to choose the S-boxes. This would suggest 16-bit key (128 bit block divided on each layer to 32 4-bit S-boxes and having 5 layers).Lauri.pirttiaho (talk) 10:39, 30 January 2011 (UTC)Reply