This is a very simple alphabet cipher, but the key to making it easy is knowing the key number. Say the key number is 5. A becomes F, J becomes O, and Z becomes E and so on. “Adam rakes his yard” becomes, “FIFR WFPJX MNX DFWI.” Whoever you are sending your secret code to must know the key number or they wont be able to break the code.
A=1, B=2, C=3 etc, all the way to Z=26. This cipher wouls be very easy to break on its own, but add the Caesar Code to it and you will make anyone trying to break the code go mad. In the basic method, “the dog is better” would be “20 8 5-4 15 7-9 19-2 5 20 20 5 18.” But say you add a Caesar Cipher number key of 3, this same message becomes “3 23 11 8-7 18 10-12 22-5 8 23 23 8 21.” Once again, the key to deciphering this code is the know the key number.
A B C D E F G H I J K L M
N O P Q R S T U V W X Y Z
In this sequence, “How are You?” would be, “UBJ NER LBH”
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Z Y X W V U T S R Q P O N M L K J I H G F E D C B A
In this sequence, “How are You?” would be, “SLD ZIV BLF”
You and the reader both need to have the right alphabet sequence or this cipher wont work.
Take a normal piece of Xerox paper and cut a ½ inch slice of it the long way. Wrap this tightly around a brand new pencil. Write one or two letters on each little wind so that you have a clear message. Now unwind the paper and write more letters all over the place so that it looks like its only a bunch of gibberish. Give this piece of paper to someone else with a brand new pencil and have them wrap the note around it and they will be able to get the hidden note.
This is modeled after the second example in the Alphabet Ciphers.
You and whoever you are passing the code on to need to agree on a key word. Say the key word is, “BAIT.” This is what the alphabet would look like. (Keep in mind that the letters you use don't get repeated so just skip right over the ones that have already been used.)
B A I T Z Y X W V U S R Q P O N M L K J H G F E D C
In this alphabet, “I'll be back” would be “VRR AZ ABIS.”
A ._
N _.
1. _ _ _ _
B _…
O _ _ _
2.._ _ _
C _._.
P . _ _ .
3..._ _
D _..
Q _ _ ._
4 …._
E .
R ._.
5 …..
F .._.
S …
6 _….
G _ _.
T _
7 _ _…
H ….
U .._
8 _ _ _..
I ..
V …_
9 _ _ _ _.
J ._ _ _
W ._ _
0 _ _ _ _ _
K _._
X _.._
L ._..
Y _._ _
M _ _
Z_ _..
这是一种非常简单的字母序列密码，但是简化它的关键在于知道其密钥。比如密钥数字是5。A就成了F，J就成了O，Z就成了E……依此类推。 “亚当在院子里耙地”（Adam rakes his yard）就成了“FIFR WFPJX MNX DFWI.”你的密码接受者必须知道这个密钥，否则他们无法破解密码。
A=1, B=2, C=3依此类推，一直到Z=26。这个密码本身很好破解，但是与凯撒密码一结合你就能让任何一个破密者头疼了。用这个基本方法，“这只狗更好”（the dog is better）将转换为“20 8 5-4 15 7-9 19-2 5 20 20 5 18”但是，比方说，你给它加一个凯撒密钥3，此信息就成了“ 3 23 11 8-7 18 10-12 22-5 8 23 23 8 21”同样，要破解此密码必须了解密钥。
在这种序列下，“你好吗”（How are you?）就成了“UBJ NER LBH”
在这种序列下，“你好吗”就成了“SLD ZIV BLF”
你和阅读者需要得到正确的字母序列，不然就无法解读密码。
取一张常见的施乐复印纸，裁成½英寸宽的细条。把它紧密地包裹在新铅笔上。在每一圈上写上一或两个字母组成你所要表达的信息，把纸条展开，在空白部分添加更多字母使之看上去就像一串乱码。把纸条与新铅笔给别人，唯有将它们相互缠绕才能得到隐匿的信息。
这个密码仿造字母序列密码中的第二个例子。
你和密码接收者需要一个共同的密钥字母。比如密钥是“BAIT”，这将成为字母序列的关键。（记住你所用的字母，在后面排列时跳过它们）
在这种字母顺序下，“我会回来的”（I'll be back）就成了“VRR AZ ABIS”。
①“恺撒密码”据传是古罗马恺撒大帝用来保护重要军情的加密系统。（既是今天我们所说的：替代密码）它是一种置换密码，通过将字母按顺序推后起3位起到加密作用，如将字母A换作字母D，将字母B换作字母E。据说恺撒是率先使用加密函的古代将领之一，因此这种加密方法被称为恺撒密码。
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