I Digital wills and inheritance
Schedule a private capsule with crypto-asset keys, legacy passwords or inheritance instructions. It renews and stays inaccessible while you remain active.
Professional · Legacy
Time capsuleson the Blockchain
Leave a message in time. Blockchain technology guarantees that your capsule exists, stays intact and only opens when you decide.
- No intermediaries
- Immutable date
- Total privacy
What is a time capsule
A time capsule is a message you keep today so that someone opens it on a specific date in the future. For generations they were buried in foundations, gardens and cornerstones. Capschain turns it into a digital object that no one can alter or open early.
You write, attach your files and choose who can open it and when. Your content is encrypted end to end and only its cryptographic fingerprint, a hash, is recorded on the blockchain.
That fingerprint is public proof that the capsule existed at that exact moment and that not a single comma has changed. When the date arrives, the capsule opens for its recipient. Not before, and not any other way.
- No intermediaries
- You control the content, the recipients and the date. No third party can open it for you.
- Immutable date
- The on-chain record proves when it was sealed and fixes when it opens.
- Total privacy
- Only the fingerprint lives on the blockchain. The message travels encrypted.
A message that travels unaltered.
Every capsule combines end-to-end encryption with public proof of existence.
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I
Create
Write, upload your files and choose who will be able to open them.
Message · files · recipients -
II
Seal
Your content is encrypted. Only its cryptographic fingerprint is recorded on the chain.
SHA-256 → Polygon -
III
Unlock
When the date arrives, the capsule opens for its recipient.
Date = lock
The future needs witnesses.
From protecting assets and sensitive information to keeping family memories, a capsule turns a future date into a verifiable guarantee.
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II Sealed-bid tenders
Every company submits its bid encrypted. On opening day they unlock at the same time, with no leaks and no early access for the organiser.
Professional · Transparency
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III Bonds and temporary NDAs
Store exclusivity agreements or penalty clauses so they become public or expire automatically on the agreed date.
Professional · Contracts
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IV Source code guarantees
A developer can escrow the source code and release it automatically to the client if they disappear or breach the agreed support.
Professional · Software escrow
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V Institutional press embargoes
Media and journalists receive reports in advance to prepare their stories, but the file cannot be decrypted until the exact embargo time.
Professional · Communications
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VI Intellectual property and patents
Seal an idea before registering it elsewhere and keep verifiable prior-art proof, with date and time.
Professional · Intellectual property
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VII Growth capsules for children
Keep letters, videos and family messages to be opened strictly when the child turns 18, protected against technological loss.
Personal · Family
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VIII Messages of growth and goals
Write yourself a letter today for five or ten years from now with your goals, fears and expectations. The scheduled date stops you reading it early.
Personal · Growth
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IX Commemorative capsules
At a wedding or anniversary, guests can leave messages in a shared capsule to be opened on a special date, like your silver anniversary.
Personal · Celebrations
What is public is the proof. What is yours stays yours.
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End-to-end encryption
Content is encrypted before it is sealed. Only the recipients you choose can read it when the date arrives.
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Only the fingerprint on-chain
Only the hash of the content goes to the blockchain: a fingerprint that proves it exists and is intact, without revealing anything it says.
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Final records on Polygon
Final seals are anchored on Polygon, a public network: anyone can verify when a capsule was sealed.
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Testing on Sepolia
User tests run on Sepolia, the Ethereum test network, at no cost and with no consequences.
Try the seal
Type a message. This is how its fingerprint is computed: the only thing that would travel to the blockchain.
Demo · nothing leaves your browser
SHA-256 fingerprint
Change a single letter and the fingerprint changes completely.
It would open in —
Frequently asked questions
What is a digital time capsule?
It is a message, with text or files, kept today so that one or more recipients open it on a future date. On Capschain the content is encrypted and its fingerprint is recorded on the blockchain, so you can prove it existed and that it has not changed.
What is stored on the blockchain?
Only the cryptographic fingerprint (hash) of the content. The message itself travels end-to-end encrypted and is not published on-chain.
Which blockchain does Capschain use?
Final records are anchored on Polygon. User tests run on Sepolia, the Ethereum test network.
Can anyone open my capsule before the date?
No. The capsule stays sealed until the date and time you scheduled and only opens for the recipients you chose.
What can I keep in a capsule?
Written messages and files: letters, videos, documents, contracts, source code, inheritance instructions… and you choose who can open them.
What is a blockchain time capsule for?
For personal uses, like letters to your children, goals for your future self or wedding memories, and professional ones, like digital wills, sealed-bid tenders, NDA contracts, source code escrow, press embargoes or prior-art proof.
How do I create or open a capsule?
From the app at app.capschain.com you can send a new capsule or view the ones sent to you.
Nothing is lost.Nothing comes early.
Enter the orbitClick to open the app and send or view a capsule.