Cryptor Application Help

What does this application do?

The Cryptor app is a desktop/laptop browser application that encrypts a text message you enter using a case-sensitive passphrase. It allows you to download the encrypted result as an HTML file embedded with the encrypted data. You can then double-click the downloaded file to open it in a browser and decrypt the text using the same passphrase.

The typical use case is securely saving a list of hard-to-remember passwords.

The file cannot be decrypted without the passphrase, so it's essential to create a passphrase that is both difficult to guess and easy to remember.

Is it secure?

This is a browser-based application. No personal data, text, or passphrase is sent to a server or over the internet. The encrypted file is downloaded only to your personal device, typically in your downloads folder. The passphrase never leaves your browser and is not stored in cookies, local storage, or other locations. As with any internet application prompting for a password or passphrase, always verify the domain in the address bar.

Since the passphrase is not transmitted or stored, there is no way to recover it if lost. Choose a phrase you can remember.

Passphrase Examples

• He who is brave is free. No?
• You can totally do this.
• Try a slow count to 10, then speak.
• Choose one thing and go all in. Or not.
• I can, and I will. Smith.

Steps

1. Enter or copy/paste your message, list of passwords, etc., into the message box.
2. Enter your passphrase.
3. Click the Encrypt Message button.
4. Click the Download link.
5. Open the downloaded file, enter your passphrase, and verify the plain text content.
6. (Optional) Move the file to another location with an alternate name.

Close the browser page after verifying the encryption, especially in public settings like a café.

You can leave the file in your downloads folder, move it to another location, or even your desktop. Without the passphrase, it cannot be decrypted.

How to Access and Decrypt Your Download?

To access your secrets file, navigate to the file in Finder and double-click it. Once open, enter the passphrase and click the Decrypt button. The decrypted text will appear, and the password field and button will disappear. To hide the plaintext, close or refresh the browser page. The page will automatically time out and close after 5 minutes.

Important Things to Consider

Updating an Existing File

You can update an existing file by first decrypting it, then copying and pasting the content into a new application session. Make changes to the text, re-encrypt it, and download the updated file.

What is the Number in the Filename?

The filename secret-####.html is generated in the browser using the current date as a timestamp from JavaScript's Date.getTime() method.

What Happens When I Click the Encrypt Message Button?

The passphrase is used to encrypt the message directly in the browser (not on a server). The resulting ciphertext is embedded in the page and appended to the secrets file when you click the download link.

Browser Support

This application has been tested on the following Mac OS/OSX (Intel and ARM) desktop browsers:

• Chrome
• Safari
• Microsoft Edge (for Mac)
• Firefox (Mac and Linux)
• DuckDuckGo
• Arc Browser

Any browser using the latest version (as of 2023) of WebKit should work.

Note: This application is designed for desktop/laptop machines and is not recommended for tablets or phones.

Credits

Most of the logic for this app is based on a library under the MIT license, called portable-secret, written by Marco Primi.