MAKEKEY(ADM)                         UNIX System V



     Name
          makekey - generates an encryption key


     Syntax
          /usr/lib/makekey


     Description
          makekey improves the usefulness  of  encryption  schemes  by
          increasing  the  amount  of  time required to search the key
          space.  It reads 10  bytes  from  its  standard  input,  and
          writes  13 bytes on its standard output.  The output depends
          on the input in a way that is intended to  be  difficult  to
          compute  (i.e.,  to  require  a  substantial  fraction  of a
          second).

          The first 8 input bytes (the input  key)  can  be  arbitrary
          ASCII  characters.   The  last  2 input bytes (the salt) are
          best chosen from the set of digits, dot (.), slash (/),  and
          uppercase  and  lowercase  letters.  The salt characters are
          repeated as the first  2  characters  of  the  output.   The
          remaining  11 output characters are chosen from the same set
          as the salt and constitute the output key.

          The transformation performed is essentially  the  following:
          the  salt  is  used  to  select  one  of 4,096 cryptographic
          machines all based on the National Bureau of  Standards  DES
          algorithm,  but  broken  in 4,096 different ways.  Using the
          input key as the key, a constant  string  is  fed  into  the
          machine  and  recirculated.   The  64 bits that come out are
          distributed into the 66 output key bits in the result.

     See Also
          passwd(F)


     (printed 2/15/90)                               MAKEKEY(ADM)