More on How to Break Codes
(A continuation of the page; Code
The page on code breaking gave you a few rules about how to
break codes. They should have been sufficient to break the code
and read the message there. If not, here is the message again,
followed by the decoded version:
lbyeavb ha hpb lagyc at eacb sgbxzqwr.
hpb zbm, xi mak vxm pxjb wahqebc, qi ha ihxgh lqhp hpb iqvdyb
gkybi xsakh ybhhbg tgbfkbwem, xwc hgm wbl xddgaxepbi awym lpbw
hpbib txqy. qw ahpbg lagci, mak dyxm hpb acci ha ihxgh, xwc hpbw
xcukih makg ihgxhbrm xi wbbcbc.
hpqi qi x rgbxh sgxqw bnbgeqib. egbxhqwr
makg alw, daiiqsym kwsgbxzxsyb eacb, qi xyia x tkw lxm ha bnbgeqib
makg sgxqw. hpbgb lqyy sbe vagb aw hpxh qw xw kdeavqwr qiikb
at hpb sgxqwdalbg wbliybhhbg. hpb iksiegqdhqaw tagv qi aw hpb
pavb dxrb. lpm wah ra iqrw kd wal?
Welcome to the world of code breaking.
The key, as you may have noticed, is to start with the simple
rules about letter frequency, and try new approaches only when
these fail. In other words, you play the odds to start, and then
adjust your strategy as needed.
This is a great brain exercise. Creating
your own, possibly unbreakable code, is also a fun way to exercise
your brain. There will be more on that in an upcoming issue of
the brainpower newsletter. The subscription form is on the home
page. Why not go sign up now?
One of the easiest ways to use a frequency table to break
codes is to start by writing down the letters or symbols used
in the secret message. Then, next to each, you write the number
of times that the symbol or letter appears in the message. If
you did that in this case, you noticed that the letter "b"
occurred most often - 47 times total.
That's makes it 11.4% of the total letters (413 total), close
to the 12.7% normal frequency of the letter "e" in
written English. Of course, you don't ned to figure the percentages.
It is enough to note that it is the frequent letter, and so it
is likely to represent "e". You try that first. If
that didn't work, you would try the next most common letter (t)
and so on.
If you look for the common three letter words with "b"
in them (which represents "e"), you'll quickly see
that there are several times that "hpb" occurs. One
of the more common three-letter words ending in "e",
of course, is "the" Assuming "hpb" is "the,
you now have three of the letters decoded. Change all the letters
of "h" and "p" and "b" to "t",
"h" and "e", and the message starts to get
easier and easier to decode.
By the way, there are tools that can help you do this, including
some that you may have in your computer. If you have a spell
checker, for example, start it just before the first "hpb",
insert "the" as the correct spelling, and click the
"change all" button. That will speed things up. You
can do this repeatedly as you decipher each word.
It also helps to write the original message with double or
triple spacing. That way you have space to try several possibilities
when deciphering it. Remember too that "a" and "I"
are the only one-letter words in English. In the above message,
this makes finding the code letter for "a' very easy, and
then it is easy to find the letter "n" in "an"
and the "d" in "and".
Here is the code used to create the message:
a = x
b = s
c = e
d = c
e = b
f = t
g = r
h = p
i = q
j = u
k = z
l = y
m = v
n = w
o = a
p = d
q = f
r = g
s = i
t = h
u = k
v = j
w = l
x = n
y = m
z = o
All the pages on codes, ciphers and cryptograms are listed
on the page: Secret Codes.