9.3 THE DES S-BOXES, P-BOX, AND INITIAL PERMUTATION (IP)

Tables 9.4 to 9.11 specify the seven DES S-boxes, each with a 6-bit input (x0, x1, x2, x3, x4, x5, x6) and a 4-bit output (y0, y1, y2, y3); each table contains 4 rows and 15 columns, where

  • Bits (x0, x6) identify a row in the table, and
  • bits (x1, x2, x3, x4) identify a column in the table.

TABLE 9.4 DES S-Box S[0]

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TABLE 9.5 DES S-Box S[1]

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TABLE 9.6 DES S-Box S[2]

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TABLE 9.7 DES S-Box S[3]

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TABLE 9.8 DES S-Box S[4]

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TABLE 9.9 DES S-Box S[5]

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TABLE 9.10 DES S-Box S[6]

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TABLE 9.11 DES S-Box S[7]

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My description of DES differs slightly from that given in [FIPS, 1988] in two respects:

  • I use 0-index origin labeling; for example, a 64-bit plaintext ...

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