Bacon Cipher

Features

Bacon cipher is an ancient encryption method that encodes letters using two characters: A and B. Invented by English philosopher Francis Bacon in 1605, it's one of the earliest binary encoding methods.

Historical Background

Invented by Lord Francis Bacon, first described in his work "Advancement of Learning". Each letter is replaced with a sequence of five A's or B's, creating a steganographic encryption method.

Use Cases

• Introduction to cryptography
• Steganography research
• Fun encryption games
• Historical cryptography demonstrations
• CTF steganography challenges

Encoding Rules

Standard Bacon Cipher Table

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

How to Use

1. Enter text to encrypt
2. Click encrypt button
3. View A/B sequence encoded result
4. Can use A↔B or A↔0/B↔1 mode

Encryption Examples

Plaintext: HELLO

H = abbab
E = aabaa
L = babaa
L = babaa
O = baaba

Encrypted: abbab aabaa babaa babaa baaba
Short: abbabaabaa babaa babab aabaa

Special Rules

Steganographic Mode

The clever part of Bacon cipher is it can be "hidden" in other text:

• Use appearance of normal text
• Embed A/B encoding in sentence case
• Or embed in different fonts

Visual Hiding Example

Original text: Attack at dawn
Hidden info: ATTACK AT DAWN
            AAAAA BABBB AAAAA
            (H = AAAAA)

Security Analysis

Advantages

• Looks like normal text
• Can be hidden in other content
• Easy to implement

Disadvantages

• Large encoding (5x expansion)
• Can only encode 26 letters
• Cannot represent special characters
• Very low security in modern cryptography

Application Tips

1. Case Hiding

AAAAA = uppercase letter
BBBBB = lowercase letter

2. Font Hiding

AAAAA = normal font
BBBBB = bold/italic

3. Number Mode

A = 0
B = 1

Notes

1. Only supports English letters
2. Spaces and punctuation will be lost after encryption
3. Receiver needs to know encoding rules
4. A simple substitution cipher, not suitable for secure communication