Thonky.com »
Other »
Kryptos and Cryptanalysis Information

## Baconian Cipher

### What is the Baconian Cipher?

The Baconian cipher uses a binary system of encoding the letters of the alphabet.
For example, A is encoded with aaaaa, B is encoded with aaaab, and so on.
This method encodes a true message in a seemingly innocuous note, where the
first letters of the words in the message are converted into A or B depending on which
half of the alphabet the letter appears in. Alternatively, each letter of the encoded
message can represent an A or B in the encryption scheme.

### Example

**Letter codes**

`
A = aaaaa E = aabaa I/J= abaaa N = abbaa R = baaaa W = babaa
B = aaaab F = aabab K = abaab O = abbab S = baaab X = babab
C = aaaba G = aabba L = ababa P = abbba T = baaba Y = babba
D = aaabb H = aabbb M = ababb Q = abbbb U/V= baabb Z = babbb
`

**Plaintext:** SOS

**Coded Message:** Take a dog for the brief walk to a store where he can get treats.

**Initials:**

TADFT BWTAS WHCGT

baaab abbab baaab

baaab = S

abbab = O

baaab = S

### Vulnerabilities of Baconian Cipher

A message encoded with Baconian Cipher might sound awkward, which can help a potential solver
determine that this method is in use. In addition, the message has to have a number of words
divisible by five, because each plaintext letter is encoded using five "bits," or in this case,
As and Bs. If each letter in the ciphertext represents an A or B instead, it is also easy to see
that the number of letters will have to be divisible by five.

### How to Crack a Baconian Cipher

The hard part of solving a Baconian Cipher is merely to determine that this is the method in use.
Once you figure that out, it's simple to take the letters of the message and convert
them into the plaintext.

Page last updated 2014-11-28T02:01:27+01:00