App Personal — open source

The Crypt-in Personal Windows app is licensed GPL-3.0, and its source is published as a beta at github.com/jaffa2970/cryptin-sdk-beta since 17 October 2026 — so you can build it, fork it and port it today. Contributions are a different matter: during the beta the repository takes no issues and no pull requests.

Licence: GPL-3.0  |  Binary: /beta/

The SDK it uses is Apache-2.0, which is compatible with GPL v3 — that compatibility is why the app is v3 and not v2. See Licence.

Source: github.com/jaffa2970/cryptin-sdk-beta, src/CryptinPersonal/. The beta package is a separate release and ships binaries only. The dongle firmware is not in the repository and stays closed source.

What the app does

• Detects the Crypt-in dongle over USB HID
• Authenticates with the PIN
• Encrypts files to .crin by drag and drop
• Decrypts .crin files
• Guides the first-boot backup of seed and PIN
• Activates the licence against the licence server

What the app does not do

• It contains no cryptographic keys
• It sends no secrets to lake8.dev
• It cannot decrypt anything without the dongle

That last point is the one worth testing yourself: unplug the dongle and the app becomes a file browser that opens nothing.

Build from source

Beta sources, published as they are

The repository is the code of the public beta: not a supported release, the API may change without notice, and there is no support channel for it. The commands below do work.

The client links CryptinSDK 1.0.0, which ships on .NET 9 in both published artefacts — see the runtimepack version in the CLI SBOMs. A .NET 8 project cannot reference a net9.0 assembly, so .NET 9 is the floor, not a preference.

git clone https://github.com/jaffa2970/cryptin-sdk-beta.git
cd cryptin-sdk-beta

# Requirements: .NET 9 SDK (Visual Studio 2022 17.12 or later)
dotnet build CryptinSDK.sln -c Release
dotnet run --project src/CryptinPersonal -c Release

App Personal targets net9.0-windows and builds on Windows only; the library, the CLI and the tests build anywhere .NET 9 runs.

The repository does not contain the firmware image. For the Program button to work, take firmware/firmware.factory.bin from the beta package and put it next to the executable.

Architecture

The app is the WinForms layer; everything below it lives in the SDK, which the app references. In the repository:

Path	What it is
src/CryptinPersonal/	The Windows application: main window, PIN entry, setup wizard
src/CryptinSDK/Dongle/	USB HID transport to the dongle — CryptinDongle.cs
src/CryptinSDK/	.crin file format, licence client, BIP-39 recovery phrase

The full map is the What is here table in the repository README.

The crypto layer never sees a key: the per-file key is derived on the dongle from its secret and a per-file salt, and the host only streams plaintext in and ciphertext out.

Contributing

⚠️ Not during the beta. The repository takes no issues and no pull requests. Forking is allowed by the licence — Apache-2.0 for src/CryptinSDK/ and src/CryptinCli/, GPL-3.0 for the rest — so you can build on it today, you just cannot send changes back here yet.

When contributions open, lake8.dev will review every change to the crypto layer, the licence layer and the HID protocol, and will sign the release binaries. There is no date for that, and no contrib branch or CI exists today.

The community can review UI and UX work, bug fixes with tests, platform ports, and documentation.

The firmware is never part of this repository: it stays closed source and is distributed only as a binary — signed for production, unsigned in the -dev beta build. See the open source policy.

Porting to Linux or macOS

The dongle layer uses hidapi, which is cross-platform. The UI layer is WinForms and needs replacing — Avalonia or GTK# on Linux, MAUI on macOS.

The source is published and the licence (GPL-3.0) allows a port in your own fork; the repository takes no pull requests during the beta.

Support

Questions: info@lake8.dev · Security: security@lake8.dev