Online Clipboard with Password — Private, Encrypted, No Account

Clipcroft is an online clipboard with an optional password. Set one and the clipboard becomes a private, end-to-end encrypted clipboard online — AES-GCM encryption with a key derived locally in your browser via PBKDF2. The server never sees the password or the content. No signup, no email, no app.

Why a password matters for an online clipboard

A clipboard name on its own is a shared session key — anyone who knows it can join. That's fine for low-stakes "send a URL to my own laptop" use, but it's not enough when the clipboard carries something sensitive: a one-time login code, an SSH key, a private bookmark, a password reset link.

The optional clipboard password closes that gap. With a password set, the clipboard becomes a private online clipboard: even someone who knows the clipboard name cannot read its content without also having the password. And because the password derives the encryption key locally, the server itself only ever sees ciphertext — even Clipcroft's operators cannot read what you paste.

How the encryption works

When you set a password, Clipcroft does the following entirely in your browser:

1. Derives an AES-GCM key from your password using PBKDF2 with a per-clipboard salt. This means the same password on two different clipboards produces two different keys.
2. Encrypts every text item with AES-GCM (authenticated encryption — both confidentiality and integrity) before sending it.
3. Encrypts file metadata and any short text messages relayed through the server. File contents already travel directly between browsers via WebRTC, so they never reach the server in any form.
4. Encrypts the local persistence too. The items kept in the browser's localStorage are themselves AES-GCM ciphertext (envelope-encrypted with the same derived key) — not plaintext JSON. Someone with momentary access to your browser's storage cannot read your clipboard items without the password.

The decryption side mirrors this: another browser with the same clipboard name and password derives the same key, and only then can it read the content. The key never leaves either device. There is no master key on Clipcroft's side — the system is structurally incapable of reading the encrypted clipboards.

Three layers in one model: encryption in flight (text relayed via SignalR), encryption at the relay (file metadata and control messages), and encryption at rest (the localStorage blob). Many "encrypted clipboard" services do one of these; combining all three with a locally-derived key is uncommon.

AutoForget — auto-lock on idle

For password-protected clipboards, Clipcroft includes an AutoForget feature. After a configurable idle window — set in Settings — the clipboard automatically locks itself and forgets the decryption key. To read the items again, you re-enter the password.

AutoForget is built around two practical safety rails: it defers if a transfer is in flight (so it never interrupts a running upload), and the idle window restarts whenever a transfer ends (so an active session doesn't get yanked out from under you). The result is an "auto-lock when you leave it alone" without any "wait, where did my upload go?" surprises.

Useful when:

• You're on a shared laptop or family computer and don't want a sensitive clipboard sitting unlocked while you step away.
• You've handed off a device to someone briefly and don't want them to see the history.
• You're working in a coffee shop and the laptop screen-locks but the browser tab remains open.
• Compliance / policy requires automatic timeouts on sensitive sessions.

Use cases

Sharing a one-time login code or magic link

Open a password-protected clipboard on the laptop you're logging in from and on the phone where the SMS / authenticator code lands. Paste the code on the phone, read it on the laptop. No SMS-forwarding, no inbox involvement, no third-party messaging app.

Moving a credential between work and personal devices

You need to give yourself an SSH key, a deployment token, or a temporary API key on another device. A password-protected clipboard is a 30-second transfer with end-to-end encryption — and the items expire from local storage after 3 days by default.

A private pastebin for personal notes

Treat the clipboard as a private pastebin: paste text on one device, retrieve it on another with the password. Because the contents are end-to-end encrypted, the clipboard isn't readable by anyone who happens to guess the clipboard name.

Sharing sensitive content with one specific person

Share the clipboard link through any convenient channel (email, chat, QR code) and the password through a different channel (in person, phone call, SMS). That way no single channel carries both halves.

How this compares to other "encrypted" clipboards

Many "encrypted clipboard" services rely on TLS or a server-held key. The data is encrypted between you and the server, but the server itself can read the content. That model is fine for many uses, but it isn't end-to-end. Clipcroft's password-derived key never reaches the server, which means the server cannot decrypt your data even under a subpoena, a misconfiguration, or a compromise.

Compare against the open-source Pastebin clones: most don't offer in-browser encryption at all, and the ones that do typically generate a random URL fragment as the key (PrivateBin-style). That's a strong pattern, but it requires you to hand someone a long random URL. Clipcroft's password model lets you choose a memorable secret and split the channels — link on one path, password on another.

Frequently asked questions

Is Clipcroft an online clipboard with a password?

Yes. Every Clipcroft clipboard supports an optional password. When set, the clipboard becomes a private, end-to-end encrypted clipboard online — AES-GCM encryption with a key derived from your password using PBKDF2, all in the browser. The server never sees the password or the unencrypted content.

How is the encryption different from regular HTTPS?

HTTPS protects data in transit between the browser and the server, but the server can still see the content. End-to-end encryption with a password protects the content from the server itself: the server only ever holds ciphertext, and the key never leaves either device. If our infrastructure were ever compromised, an attacker could not read your clipboard.

Where is my password stored?

Nowhere on our side. The password is used in your browser to derive an AES-GCM key with PBKDF2; that key is held in browser memory for the session. We never receive the password and never store a hash of it. If you forget it, the only way to recover the data is to re-create the clipboard from the device that still holds the items.

Can I use this as a private pastebin?

Yes. Set a password and use Clipcroft as a private pastebin: paste text on one device, open the clipboard on another with the password, and read it. Items live in the browser's local storage for 3 days by default and you can clear them at any time.

Does the password protect file transfers too?

Files already travel directly between browsers via WebRTC, so they never touch the server in plaintext. With a clipboard password set, file metadata and the small text messages relayed through the server are also AES-GCM encrypted, completing the end-to-end picture.

Are clipboard items encrypted on disk too?

Yes, when a password is set. The clipboardElements blob in your browser's localStorage is itself AES-GCM ciphertext, envelope-encrypted with the same password-derived key. Someone with momentary access to the browser's storage — a malicious extension, a snooper at the devtools console, or another user on the same machine — cannot read your items without the password. Without a password, the local blob is plaintext JSON; the password upgrade extends end-to-end encryption from the wire and relay layers down to the disk layer.

Does Clipcroft auto-lock if I step away?

Yes, for password-protected clipboards. AutoForget is a configurable idle timer in Settings — after the chosen number of minutes of inactivity, the clipboard locks itself and forgets the decryption key. To read the items again, you re-enter the password. AutoForget defers if a transfer is in flight and the idle window restarts when a transfer ends, so it never cuts off an in-progress upload.