About qub

Seal it now. Prove it later.

qub lets you seal a message with a future reveal date. Once sealed, it can't be read, edited, or deleted — by you, by us, or by anyone — until the date you chose. Then it reveals, and you have permanent proof of what you said and when you said it.

What you can do with it

Predictions. Call an outcome before it happens. Earnings, elections, sports, market moves. When the dust settles, you have a timestamp nobody can argue with.

Letters to your future self. Write to where you want to be in a year. Five years. Ten. The reveal lands when you do.

Bets and dares. Settle the argument permanently. Sealed today, opened on the day. No "that's not what I said."

Proof of ideas. Timestamp a thesis, a script, a design before you share it. If someone "happens to come up with" the same thing later, you have receipts.

Agreements. Use a qub pact to seal structured terms between two parties. Pick a template (sale of goods, service agreement), fill in the details, and share a link. Your counter-party reviews the terms, verifies their email, and co-signs. Both sides commit to the exact same bytes before the reveal date. No edits in between, no he-said-she-said after.

Embargoes and announcements. Pin the news to a release date. The link is shareable now; the content lands the moment you said it would.

Embed in your own site. Paste a one-line snippet into a blog post, Notion page, Substack issue, or any HTML, and the live countdown — and the reveal, when the date arrives — renders inline on your page. Decryption still happens inside the embed in the viewer's browser, so qub's servers are never in the trust chain.

How it works

1. Write. Type your message in the compose box. Format with Markdown — headings, bold, italic, lists, blockquotes, code blocks. No account required.
2. Seal. Pick a reveal date and confirm. Your message is encrypted on your device and uploaded to permanent public storage.
3. Share. Send the link. Before the date, visitors see a countdown. On the date, the message reveals and the proof speaks for itself.

Everything important happens in your browser. Your plaintext never touches our servers.

Sign your work. Generate a signing key in your browser and attach a cryptographic signature to every qub you seal. Verify your email against your key to make your identity visible to viewers. Your private key never leaves your device.

Get notified. Anyone viewing a sealed qub can subscribe to get an email the moment it reveals. One email, on the day — no spam, no account needed.

Technical details

qub uses timelock encryption tied to the drand randomness beacon, a decentralised public source of randomness that produces a new value every 3 seconds. Your message is encrypted to a future beacon value that doesn't exist yet — when that value is published at the reveal time, the message becomes decryptable. No single party (including qub) holds the keys before that moment.

The encrypted ciphertext is stored on Arweave, a permanent public ledger. Once uploaded, it can't be modified or deleted by anyone. The integrity hash printed in every reveal lets viewers verify the content hasn't been tampered with — the same bytes that were sealed are the bytes that get revealed.

Authorship signatures use ML-DSA-65, a post-quantum digital signature algorithm (FIPS 204). The full protocol spec is open source at qub.social/protocol, and our approach to safeguarding the wider stack is documented at qub.social/security.

What we don't do

No account. You don't sign up. There's no profile, no password, no recovery flow. Sealing a qub requires nothing but a browser.

Email is optional. Some features ask for an email — signing in, verifying your identity, subscribing to a reveal, or buying a paid tier. Each is used only for that purpose. No marketing, no profiles. See our privacy policy for details.

No tracking. No advertising trackers, analytics pixels, or third-party marketing scripts.

We can't read your qubs. Encryption and decryption happen in your browser. The keys come from drand, not from us. Even if we wanted to, we couldn't read a sealed qub before its reveal date — the math doesn't allow it.

We can't delete them either. Once a qub is on Arweave, it's there permanently. We can block content from displaying in the qub viewer, but the underlying data isn't ours to remove.

For developers and AI agents

The qub API lets you seal, read, and verify qubs programmatically. There's also an MCP server so AI agents can create and read qubs directly. Webhooks notify your systems when a qub reveals.

See qub.social/developer for the API reference, MCP setup, and tier details.

Pricing

Free — 5 qubs. No account, no credit card.

Creator — $19 USD. 50 qubs with extended size limits.

Builder — $29 USD/month. 200 qubs/month, API access, server-side seal, webhooks, and higher rate limits.

Enterprise — custom volume. Get in touch.

Frequently asked questions

Can I delete a qub after sealing it? No. Content on Arweave is permanent. This is by design — it's what makes the commitment credible.

Can qub read my message before the reveal date? No. Encryption and decryption happen entirely in your browser. We never see your plaintext, and the timelock keys come from drand, not from us.

What if drand stops working? drand is a distributed network operated by multiple independent organisations worldwide. If it went offline, locked qubs would remain locked until it resumed. This is a theoretical risk, not a practical one.

What is a qub pact? A pact is a structured agreement between two parties. The drafter picks a template (sale of goods, service agreement), fills in the details, and shares a staging link. The counter-signer reviews the exact terms, verifies their email address, and co-signs. Once both parties commit, the pact seals with cryptographic proof of who agreed to what — and when the reveal date arrives, it unseals with both signatures still attached.

Can I format my qub? Yes. qub supports a safe subset of Markdown: headings, bold, italic, strikethrough, lists, blockquotes, code blocks, and horizontal rules. Links and images are stripped for safety — URLs display as plain text.

Is there an API? Yes. See qub.social/developer.

Can I embed a sealed qub on my own site? Yes. Paste <script async src="https://qub.social/embed.js"></script> once, then drop a <qub-embed qub="…"></qub-embed> tag wherever you want it to render. Every qub's share, countdown, and reveal page has the snippet ready to copy under "Embed on your site".

How do I report problematic content? Every qub has a report button. We maintain a denylist to block content that violates our terms from displaying in the qub viewer.

Contact

Email: support@qub.social

Seal your words.