CAESAR(6) BSD Games Manual CAESAR(6)NAME
caesar, rot13 — decrypt caesar cyphers
SYNOPSIScaesar [rotation]
DESCRIPTION
The caesar utility attempts to decrypt caesar cyphers using English let‐
ter 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 spe‐
cific rotation value.
The frequency (from most common to least) of English letters is as fol‐
lows:
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