1CAESAR(6)                      BSD Games Manual                      CAESAR(6)
2

NAME

4     caesar, rot13 — decrypt caesar ciphers
5

SYNOPSIS

7     caesar [rotation]
8

DESCRIPTION

10     The caesar utility attempts to decrypt caesar ciphers using English let‐
11     ter frequency statistics.  caesar reads from the standard input and
12     writes to the standard output.
13
14     The optional numerical argument rotation may be used to specify a spe‐
15     cific rotation value.
16
17     The frequency (from most common to least) of English letters is as fol‐
18     lows:
19
20           ETAONRISHDLFCMUGPYWBVKXJQZ
21
22     Their frequencies as a percentage are as follows:
23
24           E(13),  T(10.5),  A(8.1),  O(7.9),  N(7.1), R(6.8), I(6.3), S(6.1),
25           H(5.2), D(3.8),  L(3.4),  F(2.9),  C(2.7),  M(2.5),  U(2.4),  G(2),
26           P(1.9),  Y(1.9),  W(1.5),  B(1.4),  V(.9),  K(.4),  X(.15), J(.13),
27           Q(.11), Z(.07).
28
29     Rotated postings to USENET and some of the databases used by the
30     fortune(6) program are rotated by 13 characters.
31
32BSD                            November 16, 1993                           BSD
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