Simple Folder Encryptor

中文说明

Simple Folder Encryptor is a Windows 11 desktop app that packages one file or one folder into a password-protected .sfe archive.

The interface is English by default. Chinese can be selected from the Language menu.

Requirements

• Windows 11
• No network access is required by the app
• For building from source: Visual Studio or Visual Studio Build Tools with .NET Framework 4.8 targeting support

Install

Download the latest files from the GitHub Releases page.

Installer EXE

1. Download FolderEncryptor-Setup-Windows11-x64.exe.
2. Run the installer.
3. Launch Simple Folder Encryptor from the Start menu.

The installer uses a per-user install location and does not require administrator permissions.

Portable ZIP

1. Download FolderEncryptor-Windows11-x64.zip.
2. Extract the ZIP to a folder you control, such as Documents\FolderEncryptor.
3. Run FolderEncryptor.exe from the extracted folder.

The release builds are currently unsigned. Windows SmartScreen may show a warning for downloaded files.

Features

• Encrypts one file or one folder into a visible .sfe package next to the source.
• Keeps the original source file or folder unchanged after encryption.
• Verifies the generated .sfe package before reporting success.
• Decrypts a .sfe package into a selected output folder with the correct password.
• Includes a custom picker that can select hidden files and hidden folders.
• Uses streaming IO for large files.
• Uses AES-256-CBC encryption and HMAC-SHA256 verification.
• Runs locally and does not use network access.
• Prevents multiple app windows; launching again restores the existing window.

Important safety notes

There is no password recovery. If the password is lost, this app cannot restore the .sfe package.

The original source file or folder is kept after encryption. Delete originals manually only after you have confirmed that the encrypted package can be decrypted.

This project has not received an independent security audit. Use it only for files you are legally allowed to store and protect.

Build from source

Open FolderEncryptor.sln in Visual Studio, or run:

build.bat

The compiled program is written to:

bin\Release\FolderEncryptor.exe

build.bat uses the .NET Framework C# compiler available on Windows. If it cannot find csc.exe, install Visual Studio or Visual Studio Build Tools with .NET desktop development support.

Code signing

Code signing is optional for normal development builds.

build.bat calls sign-output.ps1 after compilation. The signing script signs the executable only when CODE_SIGNING_CERT_SUBJECT or CODE_SIGNING_CERT_THUMBPRINT is configured and the matching certificate exists in the current user's certificate store. If no certificate is configured, signing is skipped with a warning so other developers can still build the project.

Set REQUIRE_CODE_SIGNING=1 if you want a build to fail when signing is unavailable.

License and attribution

This project is licensed under the GNU General Public License v3.0 or later. See LICENSE.

Copyright (C) 2026 YJZ.

Modified versions must preserve the copyright notices, SPDX license identifiers, and attribution to the original YJZ FolderEncryptor project. See NOTICE.

GPL allows commercial use and redistribution when the GPL terms are followed. Do not add a separate non-commercial restriction if you want to keep this project under the standard GPL.