CriptoFEP — A Classic Cipher & Analysis Toolkit

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CriptoFEP is a powerful, educational, and modular command-line toolkit written in Perl for experimenting with classic cryptography. It provides a comprehensive arsenal of historical ciphers, modern encodings, and cryptanalysis tools, making it the perfect companion for students, historians, puzzle enthusiasts, and Capture The Flag (CTF) competitors.

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📋 Table of Contents

• ✨ Core Features
• 📚 Available Algorithms & Tools
• 🚀 Quick Start
• 🛠️ Usage Guide
  • Synopsis
  • Command-Line Options
  • Practical Examples
• 📂 Project Structure
• ✅ Roadmap
• 🤝 Contributing
• 📜 License

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✨ Core Features

• Extensive Library: A vast collection of over 40 classic ciphers and 15+ standard encodings.
• Triple Modes: Intelligently separates Ciphers (secrecy), Encodings (representation), and Analysis (cryptanalysis).
• Cryptanalysis Suite: Includes tools like Frequency Analysis, Index of Coincidence (IC), and a Polyalphabetic Key Length Detector.
• Professional CLI: A robust and intuitive command-line interface with clear, consistent options.
• File I/O: Seamlessly processes direct text input or entire files.
• Full Unicode Support: Correctly handles a wide range of characters thanks to its UTF-8 architecture.
• Dynamic Help & Listing: Integrated --info, --list-ciphers, and --list-encodings flags provide detailed explanations.
• Modular & Extensible: Built with a clean architecture in lib/CriptoFEP/, making it easy to maintain and extend.

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📚 Available Algorithms & Tools

This is the complete list of algorithms and tools currently supported by CriptoFEP.

Click to expand the full list of 40+ Ciphers

Ciphers (Algorithms for confidentiality)

Name	Requires Key?	Description
ADFGX	Yes	The original 5x5 WWI German field cipher combining Polybius and columnar.
ADFGVX	Yes	The advanced 6x6 version of ADFGX, including numbers.
Affine	Yes	A mathematical substitution cipher using (ax + b) mod 26.
Albam	No	A simple substitution cipher that swaps the two halves of the alphabet.
AMSCO	Yes	An irregular columnar transposition using a 1-2 fill pattern.
Atbah	No	A simple substitution cipher with a specific, non-sequential mapping.
Atbash	No	A simple substitution cipher that reverses the alphabet (A=Z, B=Y...).
Bacon	No	A 5-bit binary encoding that maps letters to sequences of 'A's and 'B's.
Beaufort	Yes	A reciprocal polyalphabetic cipher, similar to Vigenere (C = K - P).
Bifid	Yes	A fractionating cipher combining Polybius with transposition.
Caesar	No	The classic shift cipher (fixed shift of 3).
Caesar Box	Yes	A simple columnar transposition where columns are read in natural order.
Columnar	Yes	A transposition cipher that rearranges text in columns based on a keyword.
Digrafid	Yes	An advanced fractionating cipher operating on digraphs with a 25x25 grid.
Double Columnar	Yes	Applies the Columnar Transposition cipher twice for enhanced security.
Four-Square	Yes	A polygraphic cipher using four 5x5 grids to encrypt digraphs.
Grandpré	Yes	A progressive-key polyalphabetic cipher (stronger Vigenere).
Hill	Yes	A polygraphic cipher using linear algebra (matrix multiplication).
Keyboard Shift	No	A substitution cipher based on shifting keys on a QWERTY keyboard.
Morbit	No	A fractionating cipher that combines Morse code with a simple 3x3 grid.
Multiplicative	Yes	A mathematical substitution cipher using (ax) mod 26.
Nihilist	Yes	A superencipherment combining a Polybius square with a key addition.
Playfair	Yes	The first practical polygraphic substitution cipher, using one 5x5 grid.
Pollux	Yes	A homophonic cipher that disguises Morse code using a numeric key.
Porta	Yes	A reciprocal polyalphabetic cipher using 13 substitution tables.
Rail Fence	Yes	A transposition cipher that writes text in a zig-zag pattern.
Redefence	Yes	A route cipher that writes text column-by-column and reads row-by-row.
ROT13	No	A Caesar cipher with a fixed shift of 13.
ROT47	No	A Caesar cipher that shifts all printable ASCII characters.
Route	Yes	A transposition cipher that writes text in a clockwise inward spiral path.
Scytale	No	An ancient transposition cipher simulating a cylinder (fixed at 5 rows).
Skip	Yes	A simple transposition equivalent to a Caesar Box or basic Columnar.
Three-Square	Yes	A polygraphic cipher using three 5x5 grids.
Trifid	Yes	An advanced fractionating cipher using a 3x3x3 cube.
Trithemius	No	The first documented polyalphabetic cipher (progressive Caesar shift).
Turning Grille	No	A transposition cipher using a rotating stencil with a fixed 6x6 grid.
Two-Square	Yes	A polygraphic cipher using two 5x5 grids.
VIC	Yes	A highly complex Cold War spy cipher.
Vigenère(auto)	Yes	The more secure "Autokey" variant of the Vigenère cipher.
Vigenère	Yes	The classic polyalphabetic cipher using a repeating keyword.
XOR	Yes	A modern, bitwise symmetric cipher.

Click to expand the full list of 15+ Encodings

Encodings (Standard, keyless mappings for representation)

Name	Description
A1Z26	Replaces each letter with its position in the alphabet (A=1, B=2...).
Base10	Converts characters to their standard decimal code point (ASCII/Unicode).
Base16	Represents binary data using the 16-character hexadecimal set (0-9, A-F).
Base2	Represents data in its fundamental binary format (0s and 1s).
Base32	Represents binary data using a 32-character set (A-Z, 2-7).
Base64	Represents binary data using a 64-character set. Ubiquitous on the web.
Base8	Represents binary data using the 8-character octal set (0-7).
Braille	Encodes characters into 8-dot Braille Unicode symbols.
Morse	The classic dot-and-dash telecommunication code.
NATO	The standard NATO phonetic alphabet (Alpha, Bravo, Charlie...).
Navajo	The famous word-based code used by the WWII Code Talkers.
T9	The multi-press keypad encoding from older mobile phones.
Tap Code	A Polybius-based code transmitted via taps, used by prisoners.
URL	Encodes unsafe characters for use in a URL (Percent-Encoding).

Click to expand the full list of Cryptanalysis Tools

Cryptanalysis Tools (Tools for analyzing and breaking ciphers)

Tool	Description
freq	Performs a full frequency analysis of a text, suggesting likely letter substitutions.
ic	Calculates the Index of Coincidence (IC) to help identify the cipher type.
poly-detect	Analyzes text to find the most probable key length of a polyalphabetic cipher.
digram	Performs a frequency analysis on letter pairs (digrams).
trigram	Performs a frequency analysis on letter trios (trigrams).
poly-solve	Attempts to find the key for a polyalphabetic cipher given a key length.

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🚀 Quick Start

1. Clone the Repository

git clone [https://github.com/felipeandrian/CriptoFEP.git](https://github.com/felipeandrian/CriptoFEP.git)
cd CriptoFEP

2. Display the Help Message The first command you should run is -h to see all available options.

perl criptofep.pl -h

3. List Available Algorithms To see a quick overview of all supported algorithms, use the list commands.

perl criptofep.pl --list-ciphers
perl criptofep.pl --list-encodings

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🛠️ Usage Guide

Synopsis

CriptoFEP operates in three distinct modes: Cipher, Encoding, and Analysis.

# Cipher Mode (for algorithms that hide information)
perl criptofep.pl -c <cipher> [-e|-d] [options...] ["text" | --in <file>]

# Encoding Mode (for standard, keyless representations)
perl criptofep.pl -m <mapping> [--encode|--decode] ["text" | --in <file>]

# Analysis Mode (for cryptanalysis tools)
perl criptofep.pl -a <tool> [--lang <lg>] ["text" | --in <file>]

# Utility Mode (for helper tools)
perl criptofep.pl --validate-key <cipher> <key>

Command-Line Options

General Options

Option	Description
-h, --help	Display the full help message and exit.
--list-ciphers	Display all ciphers
--list-encodings	Display all encodings
--in <FILE>	Read input text from the specified file.
--out <FILE>	Write the output to the specified file.

Mode Selection (Choose ONE)

Option	Description
-c, --cipher <NAME>	Selects Cipher Mode and specifies the cipher.
-m, --mapping <NAME>	Selects Encoding Mode and specifies the mapping.
-a, --analyze <TOOL>	Select Analysis Mode (e.g., freq, ic, poly-detect,poly-solve).
--validate-key <NAME>	Select Utility Mode to validate a key (e.g., hill).

Actions (Choose ONE per mode)

Option	Description
-e, --encrypt	Cipher mode Encrypt the input text.
-d, --decrypt	Cipher mode Decrypt the input text.
-enc,--encode	Encoding mode Encode the input text.
-dec,--decode	Encoding mode Decode the input text.
--info	Display detailed information about the selected algorithm.
--lang <lg>	Specify the language profile for analysis (e.g., en, pt, fr).
--klen <LEN>	Specify the key length (required for poly-solve).

Cipher-Specific Keys

Option	Description
-k, --key <KEY>	Provide the primary secret key.
-k2, --key2 <KEY>	Provide the second key (for doublecolumnar, twosquare, etc.).
-k3, --key3 <KEY>	Provide the third key (for 'threesquare').
--grid-key <KEY>	Provide the grid generation key (for adfgx, adfgvx).
--pattern-key <VAL>	Provide the pattern key (for amsco, e.g., "1221").
--date <DATE>	Provide the date (for 'vic' cipher).

Practical Examples

1. Encrypt with the VIC cipher

perl criptofep.pl -c vic -e -k "A SIN TO SIN" --date "171025" "ATTACK AT DAWN"

2. Decode a Base64 string

perl criptofep.pl -m base64 --decode "SGVsbG8gV29ybGQ="

3. Analyze a ciphertext to find its key length

perl criptofep.pl -a poly-detect --lang en "VPOVEWZTVMVIXRKSVIUGZGSVGIZBHOLYRZMZKKILEZXS"

4. Check the Index of Coincidence of a text

perl criptofep.pl -a ic "VPOVEWZTVMVIXRKSVIUGZGSVGIZBHOLYRZMZKKILEZXS"

5. Encode a file's content using the NATO alphabet and save it to another file

perl criptofep.pl -m nato --encode --in message.txt --out nato_encoded.txt

6. Get detailed information about the historic Playfair cipher

perl criptofep.pl -c playfair --info

7. Break a Vigenère Cipher (Two-Step Attack)

Step 1: Find the key length with poly-detect.

perl criptofep.pl -a poly-detect "GZTZIWTTZBVVMPMVVLJRIVEXSOTUDXCZLZXTHSMIRLTDHCZPVVCXUZSPVSNSVLSOIFVIIH
KJEYIEVIIGKKEIGKHPJWUHFPREPOIETIEH"

(Output: ...The most probable fundamental key length is 5.)

Step 2: Solve for the key using the length you found.

perl criptofep.pl -a poly-solve -klen 5 "GZTZIWTTZBVVMPMVVLJRIVEXSOTUDXCZLZXTHSMIRLTDHCZPVVCXUZSPVSNSVLSOIFVIIH
KJEYIEVIIGKKEIGKHPJWUHFPREPOIETIEH"

(Output: ...The most probable key is 'CHAVE'.)

📂 Project Structure

.
├── 📜 criptofep.pl          # The main command-line interface (controller)
│
├── 📂 lib/
│   └── 📂 CriptoFEP/       # Directory for all Perl modules (the core logic)
│       ├── 📜 Utils.pm     # Shared helper functions (e.g., text normalization)
│       ├── 📜 Analyzer.pm  # The cryptanalysis module
│       ├── 📜 Cesar.pm     # Each cipher has its own dedicated module...
│       ├── 📜 Morse.pm     # Each encoding has its own dedicated module...
│       └── ...           # ...and so on for all algorithms
│
├── 🔬 t/                   # Directory for the automated test suite
│   ├── 📜 01-cesar.t     # Each module has a corresponding test file...
│   └── ...
│
├── 📄 README.md              # This documentation file
│
└── ⚖️ LICENSE               # The MIT License for the project

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✅ Roadmap

• Implement a comprehensive library of classic ciphers and encodings.
• Create a professional, modular architecture.
• Add a robust command-line interface with file I/O and dynamic help.
• Implement a powerful cryptanalysis suite (Freq Analysis, IC, Key Length Detector).
• Next Up: Complete the automated test suite to achieve 100% coverage.
• Add more unique and challenging ciphers (e.g., Book Cipher, Enigma).
• Create a LEIA-ME.md file with a full Portuguese translation.

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🤝 Contributing

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement".

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📜 License

This project is licensed under the MIT License. See the LICENSE file for details.