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CAESAR(6) FreeBSD Games Manual CAESAR(6)
NAME
caesar, rot13 - decrypt caesar ciphers
SYNOPSIS
caesar [rotation]
rot13
DESCRIPTION
The caesar utility attempts to decrypt caesar ciphers 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 invoked as rot13, a rotation value of 13
will be used.
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.
FreeBSD 14.0-RELEASE-p6 November 16, 1993 FreeBSD 14.0-RELEASE-p6