Secure Time Capsule

Send a message to the future

The capsule opens exactly on the date and time you select. Protected by Zero-Knowledge encryption and drand randomness so nobody can peek early.

  • This link is 100% Zero-Knowledge. Content stays encrypted in your browser. drand guarantees nobody can unlock the capsule before the scheduled round completes.

  • This link is safe to bookmark or print. No one can read it until the opening time.

  • Help recipients remember the moment with automated reminders that respect privacy.

  • Encryption happens in your browser
  • The key is never sent to our server
  • Messages disappear automatically
  • No account required

How it looks

From sealing to opening

Step 1 · Sender

Share or store this link in a safe place. Only someone with the full URL (including the # fragment) can decrypt the capsule when the time arrives.

Secure capsule link

https://mboxly.link/:id#…key

Copy link Download PDF with QR Print as letter

Store the PDF in a vault, testament, or safe envelope.

Step 2 · Recipient (waiting)

Time remaining

3 years · 47 days · 12 hours · 38 minutes

From
alex@future.family
Capsule title
Letter to my daughter on her 18th birthday

Too early. The capsule unlocks on the scheduled date.

Step 3 · Recipient (unlocked)

Capsule unlocked

Fetching randomness from the drand network...

Capsule contents

Download everything Forward as new link Print keepsake

Reminders & delivery confidence

Help recipients remember the moment with automated reminders that respect privacy.

7-day reminder

We send a gentle reminder seven days before opening with the countdown and secure link.

Day-of alert

On the exact opening date we notify the recipient with the link, countdown, and instructions.

Self reminder

Optionally notify the sender as well, perfect for future letters to yourself.

Why Secure Time Capsule?

Some memories deserve a dramatic reveal. Secure Time Capsule lets you seal letters, videos, and promises with verifiable randomness so the surprise happens exactly on the chosen day.

It is ideal for milestone birthdays, legacy planning, startup mission letters, or personal commitments to your future self.

How the capsule workflow operates

1. Content is encrypted locally, including attachments.

2. The opening schedule is anchored to a drand randomness round so it cannot be accelerated.

3. Recipients see a beautiful countdown until the unlock moment.

  • Zero-Knowledge encryption Only the final link fragment contains the key. We cannot read or reveal the capsule content.
  • Verifiable randomness drand is a public randomness beacon. Each round has a cryptographic proof that the event happened at a specific time.
  • Ceremonial delivery Recipients experience a cinematic countdown, not just a bland file download.

Use cases

Family milestones, legal instructions, personal growth letters, startup manifestos, wedding videos, investor updates, classrooms projects, and memories for kids.

  • Legacy planning Attach a PDF, video, or letter for heirs with instructions that activate later.
  • Personal commitments Write to your future self and set reminders so you cannot forget.
  • Celebrations Reveal college acceptance letters, mission statements, and vows when the moment arrives.

Secure Time Capsule FAQ

How does drand guarantee nobody can open early?

drand (Distributed Randomness Beacon) publishes unpredictable randomness at fixed intervals. Each capsule references a future drand round, so the decryption key cannot be derived until that round is publicly released.

Can I edit the capsule after creating it?

No. To preserve integrity, the capsule is sealed once it is encrypted. If you need to change something, create a new capsule and share the updated link.

What happens if the recipient loses the link?

Because this is Zero-Knowledge, we cannot recreate the key fragment. Encourage recipients to download the PDF or print the instructions so they always have a copy.

Are reminders private?

Yes. Reminder emails or SMS only contain the countdown and a link placeholder. The actual content remains encrypted until the unlock moment.