Decrypt-an-encrypted-message-lab.ipynb

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    "## Scenario\n",
    "\n",
    "In this scenario, all of the files in your home directory have been encrypted. You’ll need to use Linux commands to break the Caesar cipher and decrypt the files so that you can read the hidden messages they contain.\n",
    "\n",
    "Here’s how you’ll do this task: First, you’ll explore the contents of the home directory and read the contents of a file. Next, you’ll find a hidden file and decrypt the Caesar cipher it contains. Finally, you’ll decrypt the encrypted data file to recover your data and reveal the hidden message.\n",
    "\n",
    "OK, it's time to decrypt some messages in Linux!"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "The tr command translates text from one set of characters to another, using a mapping. The first parameter to the tr command represents the input set of characters, and the second represents the output set of characters. Hence, if you provide parameters “abcd” and “pqrs”, and the input string to the tr command is “ac”, the output string will be “pr\". "
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    "In this case, the command `tr \"d-za-cD-ZA-C\" \"a-zA-Z\"` translates all the lowercase and uppercase letters in the alphabet back to their original position. The first character set, indicated by \"d-za-cD-ZA-C\", is translated to the second character set, which is \"a-zA-Z\"."
   ]
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   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "`openssl aes-256-cbc -pbkdf2 -a -d -in Q1.encrypted -out Q1.recovered -k ettubrute`"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "In this instance, the openssl command reverses the encryption of the file with a secure symmetric cipher, as indicated by AES-256-CBC. The -pbkdf2 option is used to add extra security to the key, and -a indicates the desired encoding for the output. The -d indicates decrypting, while -in specifies the input file and -out specifies the output file. The -k specifies the password, which in this example is ettubrute."
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "![image](https://github.com/user-attachments/assets/b362ac51-9795-4199-baef-feb3365bf126)"
   ]
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