NAME    [Toc]    [Back]

     caesar, rot13 - decrypt caesar cyphers

SYNOPSIS    [Toc]    [Back]

     caesar [rotation]
     rot13

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.

     If  this  utility  is invoked as rot13, it will rotate by 13
characters.
     This format is commonly used on USENET and in  some  of  the
databases used
     by the fortune(6) program to ``disguise'' their content.

     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).

OpenBSD      3.6                        November     16,     1993