decryptd

A volunteer GPU worker for decrypt. Run it on a machine with an NVIDIA GPU and it quietly does distributed compute jobs in the background: it asks the coordinator for a chunk of work, runs it on your GPU, sends the result back, and repeats — forever, until you stop it. Run and forget.

Requirements

• A CUDA-capable NVIDIA GPU.
• An up-to-date NVIDIA driver. No CUDA toolkit needed.
• Linux or Windows (64-bit).
• Linux only: the release binary includes the system-tray UI, so it needs GTK 3 and an AppIndicator library present — libgtk-3, libayatana-appindicator3, and libxdo. These ship with essentially every desktop install. On a headless server, install them (e.g. apt install libgtk-3-0 libayatana-appindicator3-1 libxdo3) or build without the tray (cargo build --release). Windows bundles everything in the .exe.

Get it

Download the latest archive from the Releases page and unpack it:

• Linux: decryptd-linux-x86_64.tar.gz → tar -xzf decryptd-linux-x86_64.tar.gz
• Windows: decryptd-windows-x86_64.zip → extract it (right-click → Extract All)

Each archive contains a single decryptd executable.

Run it

Just run it — no configuration needed:

./decryptd        # Linux
decryptd.exe      # Windows

It loops forever: claiming work, running it on the GPU, submitting results. When there's no work available it waits a minute and checks again. Stop it any time with Ctrl-C.

Leaving it running

To keep it going after you log out:

# Linux — quick and dirty
nohup ./decryptd >decryptd.log 2>&1 &

For an always-on contributor, run it under a service manager (systemd on Linux, a scheduled task / service on Windows) so it restarts on boot.

Options

You normally don't need any of these.

Option	Default	What it does
--once	off	Do a single chunk of work, then exit (handy for testing).
--idle-secs <N>	60	How long to wait before re-checking when there's no work.
--jobs <N>	1	How many chunks to run on the GPU at once.
--workdir <DIR>	decryptd-data	Where to keep the download cache and scratch files.

Downloading the next chunk and uploading finished results always happen in the background while the GPU works, so the card stays busy. --jobs only raises how many run on the GPU simultaneously — most setups are fine with the default.

Run decryptd --help for the full list.

System-tray mode

The released binaries run as a system-tray app on Windows and Linux. decryptd sits in the tray with a right-click menu showing the version, the current status (Waiting or Running), and a Quit entry. The worker runs in the background exactly as above.

If no tray host is available (for example a Linux box with no desktop session), decryptd logs a notice and falls back to running headless. Passing --once also runs headless, with no tray.

To build a console-only binary with no tray (and no GUI dependencies), build the default feature set — see Building from source.

Building from source

You need a Rust toolchain and a CUDA toolkit (only to link against the driver library at build time — the binary still just needs the driver to run):

cargo build --release                 # console-only, no GUI dependencies
cargo build --release --features gui   # system-tray app (what the releases ship)

The binary lands in target/release/decryptd (.exe on Windows). Building the gui feature on Linux additionally needs the GTK 3 / AppIndicator / libxdo development headers (libgtk-3-dev libayatana-appindicator3-dev libxdo-dev).

License

Proprietary. See Cargo.toml.