Aegis Note

Aegis Note is a standalone encrypted note application.

• Fully offline

Aegis Note does not require internet permissions. This design structurally reduces the risk of data leakage through network connections.

• Database-free design

Each note is stored as an independent encrypted file, reducing the risk of large-scale data corruption.

• High survivability

With the correct password, encrypted notes can be restored easily across devices in the future thanks to a simple and robust file structure.

• Encryption algorithm

XChaCha20-Poly1305

• Key derivation function (KDF)

PBKDF2-HMAC-SHA256 (600,000 iterations)

• Memory protection

Encryption keys stored in memory are securely cleared when the user logs out or exits the application.

• Cross-platform compatibility

Encrypted note files can be moved and used across Windows, Linux, and Android.

• Auto lock

Automatically logs out after 5 minutes of inactivity to protect data from unauthorized viewing.

• Portability

Encrypted note files can be stored and used on portable storage devices such as external SSDs or HDDs.

1. Initial Setup (Master Password)

*Android version: You must first choose a storage folder and grant file access permissions.*

Set your password:

When launching the application for the first time, you will be asked to create a master password.

Recommended strength:

You can set a password with a minimum of 3 characters, but for security reasons a password of at least 15 characters is strongly recommended.

Strength meter:

Use the strength bar below the input field as a guide to create a strong password that is difficult to guess.

2. Folder Management (Left Pane)

Create:

Click the folder icon with the "+" symbol to create a new folder.

Rename:

Select the pencil icon to edit the folder name.

Delete:

Click the red trash icon next to the folder name to delete it.

Note:

Deleting a folder will permanently remove all files inside it.

3. File Management (Center Pane)

Create:

Click the Create button at the bottom and enter a file name.

Select the file type:

Text (.ext) or Markdown (.mde)

Note:

The file type (extension) cannot be changed later.

Rename:

Use the pencil icon to edit the file name.

Delete:

Files can be deleted individually using the trash icon next to the file name.

4. Viewing and Editing (Right Pane)

Mode switching:

When a file is selected, it opens in "View Mode".

Switch the toggle at the top to enter "Edit Mode".

Editing and protection:

Click inside the editor to begin writing.

While editing, the automatic logout timer is temporarily paused so your work is not interrupted.

Saving:

When you finish editing, make sure to press the [Save] button at the top.

The data in memory will be encrypted and written to storage.

・Password Change (Re-encrypt All Files)

Procedure:

Open the Settings menu and enter your current password and the new password (including confirmation).

Batch process:

Once executed, all stored files will be re-encrypted using the new password.

Important:

Do NOT power off the device or put it into sleep mode until the process is complete.

・Backup

All data is stored in the "user_data" folder

(or the folder specified on Android).

To back up your data, simply back up this folder.

You may also back up the entire Aegis Note directory if desired.

1. Clipboard Clearing

Click the trash icon on the login screen or the editor screen to immediately clear any text stored in the clipboard, helping prevent accidental leakage of sensitive information. 

Note: If software that saves clipboard history is installed, clearing the clipboard may not be possible.

2. Markdown Preview

Supports the following formatting:

Headings (up to level 3), bold, italic, numbered lists, bullet lists, horizontal rules, and standard tables.

• Weak passwords significantly increase security risks.
  Avoid easily guessable passwords such as "password", "123456", or your birthday.

• If Aegis Note is left logged in and unattended, others may freely operate the device and access your information.
  When leaving your device, please log out from the viewing or editing screen, or close Aegis Note.

• If the device is infected with malware (such as keyloggers or screen capture software), information may be stolen before encryption is applied.

• Aegis Note does not provide synchronization features.
  Please make sure to back up your data regularly.

• If the master password is lost, the data cannot be recovered — even by the developer.

• v1.0.1→1.0.2
  Fixed several bugs, including the issue where full-width characters could be entered in the password field, the message display issue when clearing the clipboard, and other minor fixes.