NAME    [Toc]    [Back]

     caesar, rot13 - decrypt caesar cyphers

SYNOPSIS    [Toc]    [Back]

     caesar [rotation]

DESCRIPTION    [Toc]    [Back]

     The caesar utility attempts to decrypt caesar cyphers using English letter
 frequency statistics.  caesar reads from the standard input and
     writes to the standard output.

     The optional numerical argument rotation may be used to specify a specific
 rotation value.

     The frequency (from most common to least) of English letters is as follows:


           ETAONRISHDLFCMUGPYWBVKXJQZ

     Their frequencies as a percentage are as follows:

           E(13),  T(10.5),  A(8.1),  O(7.9),  N(7.1), R(6.8), I(6.3), S(6.1),
           H(5.2), D(3.8),  L(3.4),  F(2.9),  C(2.7),  M(2.5),  U(2.4),  G(2),
           P(1.9),  Y(1.9),  W(1.5),  B(1.4),  V(.9),  K(.4),  X(.15), J(.13),
           Q(.11), Z(.07).

     Rotated postings to USENET and some of the databases used by the
     fortune(6) program are rotated by 13 characters.

BSD                            November 16, 1993                           BSD