Talk:Lucifer (cipher)

On Feistel's 1973 SciAm paper
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)