Aletheia

Aletheia is a command-line tool designed to perform decode or brute-force attacks on common ciphers. It helps you quickly test and decode encrypted text using several classical cryptographic techniques.

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🧠 Why Aletheia?

The name Aletheia comes from the Greek word meaning truth or unconcealment. The tool aims to reveal hidden messages and uncover the truth behind encrypted text.

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✨ Features

• Brute force decryption for multiple classical ciphers
• Simple and intuitive CLI interface
• Useful for CTF's, cryptography learning, and quick cipher analysis

Supported ciphers:

• xor
• atbash
• vigenere
• rail fence
• xor brute force (based on key length)
• rot13 brute force
• rot47 brute force
• affine brute force
• vigenere brute force (based on key length)
• rail fence brute force

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🛠 Requirements

• Python3
• pyinstaller (if you need a binary)

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📦 Installation

Clone the repository and create a binary:

sudo apt-get install python3 pyinstaller
git clone https://github.com/1r0nx/aletheia.git
cd aletheia
chmod +x build.sh
./build.sh
sudo cp dist/aletheia /usr/bin/

You can now use it as a simple linux commands!

Or

Clone the repository and make the script executable:

git clone https://github.com/1r0nx/aletheia.git
cd aletheia/src
chmod +x aletheia.py
./aletheia.py

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Global Help

❯ aletheia 

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usage: aletheia [-h] {xor,atbash,vigenere,rail_fence,xor_brute,rot13_brute,rot47_brute,affine_brute,vigenere_brute,rail_fence_brute} ...

decode or brute force some substitution ciphers

positional arguments:
  {xor,atbash,vigenere,rail_fence,xor_brute,rot13_brute,rot47_brute,affine_brute,vigenere_brute,rail_fence_brute}
    xor                 decode xor cipher
    atbash              decode atbash cipher
    vigenere            decode vigenere cipher
    rail_fence          decode rail fence cipher
    xor_brute           brute force xor cipher
    rot13_brute         brute force rot13 cipher
    rot47_brute         brute force rot47 cipher
    affine_brute        brute force affine cipher
    vigenere_brute      brute force vigenere cipher
    rail_fence_brute    brute force rail fence cipher

options:
  -h, --help            show this help message and exit

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🔓 Cipher Modules

-XOR

XOR Decoder

❯ aletheia xor -s "1f0d10183a10183a1834111c1811" -k key

XOR Result: this_is_a_test

❯ aletheia xor -s "1f0d10183a10183a1834111c1811" -k 6B6579

XOR Result: this_is_a_test

❯ ./aletheia.py xor -s "1f0d10183a10183a1834111c1811" -k '[107, 101, 121]'

XOR Result: this_is_a_test

Note: "[107, 101, 121]" is "key" in ascii

❯ aletheia xor -s "1f0d10183a10183a1834111c1811" -k "011010110110010101111001"

XOR Result: this_is_a_test

-Atbash

❯ aletheia atbash -s "gsrh rh zgyzhs xrksvi" 

Output:

this is atbash cipher

-Vigenère Cipher

❯ aletheia vigenere -s "dlgc mq fmeorcbi astfov" -k key

Output:

this is vigenere cipher

-Rail fence

❯ aletheia rail_fence -s "li afre nscie  sciirhpeth" -k 12 -o 11

Output:

this is rail fence cipher

-XOR Brute force

Brute force xor based on key length

❯ aletheia xor_brute -s "1f0d10183a10183a1834111c1811" -l 3 | grep key

Output:

[+] Total keys to test: 1,000,000
[+] Bruteforcing XOR keys of length 3...
101530 KEY = b'afu'  ->  b'~key\\ey\\mUwiyw'
...
201434 KEY = b'key'  ->  b'this_is_a_test'
....
923890 KEY = b'}C{'  ->  b'bNkeykeycIRgeR'

-ROT13

Brute force ROT13 substitution.

./aletheia.py rot13_brute -s "Uryyb Jbeyq"

Output:

 0: Uryyb Jbeyq
...
...
13: Hello World
...
...
25: Tqxxa Iadxp

-ROT47

Brute force ROT47 transformation.

./aletheia.py rot47_brute -s "w6==@ (@C=5P"

Output:

 0: w6==@ (@C=5P
...
...
47: Hello World!
...
...
93: v5<<? '?B<4O

-Affine Cipher

Attempts all valid affine key combinations.

./aletheia.py affine_brute -t "Fwrra Yajrt"

Output:

a =  1, b =  0 -> Fwrra Yajrt
a =  1, b =  1 -> Evqqz Xziqs
...
...
a =  9, b = 10 -> Hello World
...
...
a = 25, b = 24 -> Tchhy Ayphf
a = 25, b = 25 -> Udiiz Bzqig

-Vigenère Bruteforce

Bruteforces possible keys based on length provided. 1 < len(key) < 5.

./aletheia.py vigenere_brute -s "Rijvs Uyvjn" -l 3

Output:

[+] Test of 17576 possible keys...
[possible_key=aaa] Rijvs Uyvjn
[possible_key=aab] Riivs Tyvin
...
...
[possible_key=key] Hello World
...
...
[possible_key=zzy] Sjlwt Wzwlo
[possible_key=zzz] Sjkwt Vzwko

-Rail Fence Cipher Brute force

Tests various rail counts and offset.

aletheia rail_fence_brute -s "li afre nscie  sciirhpeth"

Output:

key = 002 | period = 000 || output = l i  sacfirier hnpsectihe
key = 002 | period = 001 || output = el i  sacfirier hnpsectih
...
...
key = 012 | period = 011 || output = this is rail fence cipher
...
...
key = 024 | period = 044 || output = ail fre nscie  sciirhpeth
key = 024 | period = 045 || output = il afre nscie  sciirhpeth

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📜 License

MIT License.

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🤝 Contributing

Contributions or suggestions are welcome! Feel free to submit issues or pull requests.