An encrypted vault for your passwords, notes and files. Everything you put in SecureBox is encrypted on your device with a key derived from your password, and only you can open it. Optionally, you can keep an encrypted copy in the cloud and sync it between devices.
Note
About this README. This guide was written by AI (Claude). I have only tested the app on Windows and Android. It also builds for macOS, Linux, iOS and the browser, but I have not tried those, so expect rough edges there.
- Text secrets: a password or note, with an optional URL, user name and extra notes.
- Encrypted files: any file, optionally compressed before it is encrypted. The original can be deleted once it is in the vault.
- Folders to organise your secrets, shown as a tree or as a mosaic of icons.
- Favorites for the secrets you open most.
- Copy to clipboard and extract a file back to disk when you need it.
- Several users on the same device, each with their own password and their own files.
- Cloud copy (optional): upload, download or sync your vault. Only encrypted files ever leave your device.
- Light and dark theme.
You need the .NET 10 SDK. Then, from this folder:
dotnet run --project SecureBox.DesktopInstall the Android workload once:
dotnet workload install androidConnect your phone with USB debugging enabled, then:
dotnet build SecureBox.Android -t:Install
- Sign up with a user name and a password. This creates your user on this device.
- Log in with the same user name and password every time you open the app.
- Press Add to create a secret or encrypt a file, and pick the folder it goes in.
- Double-click (or tap) a secret to open it. From there you can copy its fields or extract the file.
Warning
There is no password recovery. Your password is the only way to decrypt your secrets. If you forget it, the data in the vault cannot be opened by anyone, including you.
| Type | Fields | Notes |
|---|---|---|
| Secret | Name, Secret, Folder, URL, User, Other data | For passwords, PINs, notes… |
| File | File, Name, Folder, Other data, Compress, Delete origin file | For documents, photos, keys… |
Compress makes large text-like files (documents, logs) smaller in the vault. It does little for files that are already compressed, such as photos or ZIP files.
Text secrets show their fields, which you can copy. Files show their original name and an Extract button that saves a decrypted copy wherever you choose.
All your secrets and folders. Add, remove, open, and upload/download/sync with the cloud. Choose between a tree with path and size (shown at the top of this page) or a mosaic you browse folder by folder:
Only the secrets and folders you starred. Click the star on any item to add or remove it.
Vault location, theme, view mode, mosaic columns and the cloud account.
On Android the side menu moves behind the ☰ button at the top.
The cloud copy is optional and off until you sign in to a cloud account in Settings. This account is separate from your SecureBox user: it is an email and password used only for the cloud.
Note
If you build SecureBox yourself, the cloud needs your own Firebase project. See Firebase settings in TECHNICAL.md. Without it, everything else works.
Once signed in, the toolbar on the Secrets screen has three buttons:
| Button | What it does |
|---|---|
| Upload | Sends every file of your vault to the cloud. |
| Download | Writes the files in the cloud into your vault. |
| Sync | Upload, then download. |
- The files are sent exactly as they are on disk, encrypted. The cloud never sees your password or the content of your secrets.
- Nothing is deleted on either side. If a downloaded file has the same name as a different local
file, both are kept and the new one is saved as
name (1). - Files larger than about 700 KB cannot be stored in the cloud and are reported as failed.
- To open your secrets on another device, sign up there with the same user name and password, sign in to the same cloud account and press Download.
| Device | Location |
|---|---|
| Windows | %LOCALAPPDATA%\SecureBox (you can choose another folder in Settings) |
| Android | Inside the app's private storage (removed if you uninstall the app, so upload a copy first) |
Settings are kept separately, in %LOCALAPPDATA%\SecureVault\config.json on Windows.
Caution
Deleting a secret on Windows sends it to the Recycle Bin. It is still encrypted there, but empty the bin if you want it gone.
Project structure, architecture and build notes are in TECHNICAL.md.