CAESAR(6) | Games Manual | CAESAR(6)

# NAME

`caesar`, `rot13` — decrypt caesar ciphers

# SYNOPSIS

`caesar` | [rotation]

# 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.

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.

November 16, 1993 | NetBSD 11.99