🔓 Mono-Alphabetic Substitution Cipher Analysis

Decrypt the cipher text using frequency analysis and substitution techniques. Tools are provided to assist your cryptanalysis.

📋 Reference: English Letter Frequencies

Use this frequency table to guide your cryptanalysis:

🔍 Current Ciphertext: The encrypted text to be analyzed

📊 Ciphertext Frequency Analysis

Letter frequencies in the current ciphertext:

✏️ Substitution Scratchpad

Note: Cipher text is in lower case. When you replace characters, the final plaintext characters will be shown in upper case automatically.

📝 Working Area: Make substitutions and track your progress

🔄 Substitution Tools

Replace cipher characters with plaintext:

This function is case insensitive and replaces cipher text (lower case) with plain text (upper case):

Replace cipher:

with plaintext:

Undo substitutions (case sensitive):

Use this function to undo unwanted changes by specifying exact characters:

Replace text:

with text:

📜 Replacement History

🎯 Submit Your Solution

After analyzing the ciphertext and making substitutions in the workspace above, enter your final solution below:

📝 Final Plaintext: Enter the complete decrypted message
🔑 Solution Key: 26 letters (a-z), each exactly once

🛠️ Mono-Alphabetic Substitution Tool

Use this tool to encrypt/decrypt with your own key and plaintext:

📄 Plaintext: Your message to encrypt	defend the east wall of the castle
🔑 Substitution Key: 26-letter substitution alphabet
	Remove Punctuation
🔒 Ciphertext: Encrypted result