1.\" $NetBSD: caesar.6,v 1.5 1997/10/10 12:07:08 lukem Exp $ 2.\" 3.\" Copyright (c) 1989, 1991, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. All advertising materials mentioning features or use of this software 15.\" must display the following acknowledgement: 16.\" This product includes software developed by the University of 17.\" California, Berkeley and its contributors. 18.\" 4. Neither the name of the University nor the names of its contributors 19.\" may be used to endorse or promote products derived from this software 20.\" without specific prior written permission. 21.\" 22.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32.\" SUCH DAMAGE. 33.\" 34.\" @(#)caesar.6 8.2 (Berkeley) 11/16/93 35.\" 36.Dd November 16, 1993 37.Dt CAESAR 6 38.Os 39.Sh NAME 40.Nm caesar 41.Nd decrypt caesar cyphers 42.Sh SYNOPSIS 43.Nm 44.Op Ar rotation 45.Sh DESCRIPTION 46The 47.Nm 48utility attempts to decrypt caesar cyphers using English letter frequency 49statistics. 50.Nm 51reads from the standard input and writes to the standard output. 52.Pp 53The optional numerical argument 54.Ar rotation 55may be used to specify a specific rotation value. 56.Pp 57The frequency (from most common to least) of English letters is as follows: 58.Pp 59.Bd -filled -offset indent 60ETAONRISHDLFCMUGPYWBVKXJQZ 61.Ed 62.Pp 63Their frequencies as a percentage are as follows: 64.Pp 65.Bd -filled -offset indent 66E(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), 67D(3.8), L(3.4), F(2.9), C(2.7), M(2.5), U(2.4), G(2), 68P(1.9), Y(1.9), 69W(1.5), B(1.4), V(.9), K(.4), X(.15), J(.13), Q(.11), Z(.07). 70.Ed 71.Pp 72Rotated postings to 73.Tn USENET 74and some of the databases used by the 75.Xr fortune 6 76program are rotated by 13 characters. 77