IncomiQ | SecureDoc

A Windows plain-text editor built on one rule:
your document should exist in as few places, for as little time, as the operating system allows.

⬇  Download the latest release  ·  Windows 10 / 11 · single ~3.8 MB .exe · no installer

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SecureDoc is free. This is the official download for the free edition — the ready-to-run app and its documentation. No account, no sign-up, and nothing you write ever leaves your machine.

Download & run

1. Open the latest release and download securedoc.exe.
2. Verify it (see below) — it is a security tool, so confirm the file is authentic before running it.
3. Double-click it. There is nothing to install, no account to create, and nothing is sent anywhere. Your documents never leave your machine.

Verify your download

In PowerShell, from the folder you downloaded to:

Get-FileHash securedoc.exe -Algorithm SHA256

The Hash it prints must equal the value in SHA256SUMS.txt for this release:

31A4B5AF18F35C1AEFDD46493C116AB4E0CF25D5E4AE59940DA914C042F10462  securedoc.exe

If it does not match, do not run the file.

See the protections being tested

These captures show current prototype behavior: memory scanning, passphrase-strength feedback, encrypted file contents, and screen-capture exclusion.

Leak-free editor — a memory scanner searches for the visible phrase and does not find the readable document text.	Passphrase protection — strength is evaluated while the actual passphrase field stays rendered as dots.
Encrypted on disk — the SECUREDC header is visible, while the document body is stored as ciphertext.	Capture exclusion — SecureDoc is omitted from the captured desktop while surrounding windows remain visible.

What it does

Leak-free editing	The open document is held encrypted in memory the whole time — drawn one letter at a time and edited in place — so a memory scanner finds no readable copy, even while you type.
Encrypted at rest & idle	Files are XChaCha20-Poly1305 ciphertext under an Argon2id key. After a short pause the open document re-encrypts under a key held by Windows and the editor blanks.
Nothing leaks to disk or screen	No autosave, no pagefile.sys exposure, no crash dumps — and the window is hidden from screenshots and screen recorders.
Sealed passphrase, clipboard & undo	The passphrase is never shown in memory; in-app copy/paste and the undo history are encrypted too.
Process hardening	Other programs running as you can't read the app's memory; DLL-injection paths are blocked.
One portable file	A single ~3.8 MB executable in memory-safe Rust. No runtime, no telemetry, no account.

Every "no readable copy" claim is checked by an automated memory-audit test suite.

The honest limits

A security tool that oversells is worse than none. This cannot protect against:

• Admin or kernel malware — these protections stop programs running as your user, not an attacker with administrator rights, a kernel driver, or DMA access.
• What's on screen — displayed text lives in GPU memory; in-process code or a camera can still capture it.
• A key already in memory — this defeats a memory scanner, not code running inside the app.
• A forgotten passphrase — there is no recovery, no reset, no back door.
• The system clipboard — copying out to another program hands one plaintext copy to Windows.

Full detail is in THREAT_MODEL.md — read it before relying on this or describing it to anyone.

System requirements

• Windows 10 or 11 (64-bit)
• No .NET, no Visual C++ Redistributable, no administrator rights

About

SecureDoc Free Edition, built by incomiq.com.