HugCert: blockchain message certification on Polygon
HugCert is a blockchain certification service by Hugete that proves the authenticity, date, and integrity of a digital message by recording its cryptographic fingerprint (SHA-256 hash) on the Polygon blockchain. This technology provides tamper-proof timestamping, comparable to a digital notarized document, certifying that your posthumous messages and time capsules have never been modified.
The problem: digital message authenticity
A digital file can be copied, modified, or backdated without a trace. Without cryptographic proof, it's impossible to guarantee that a text is authentic and unaltered.
For messages as important as those in a Capsule — last wishes, declarations of love, letters to a child — authenticity is essential.
How HugCert works: technical process
- SHA-256 Hash: your Hugz content is transformed into a unique 64-character digital fingerprint. Any change, even a single character, produces a completely different hash
- Blockchain recording: this hash is recorded on the Polygon blockchain (mainnet) via an on-chain transaction. The record is irreversible and publicly verifiable
- PDF Certificate: a signed PDF is generated with the hash, exact date, Polygon transaction ID, and a QR code for instant verification
Why the Polygon blockchain?
- Very low fees: a few cents per transaction (vs several euros on Ethereum L1)
- Speed: confirmation in seconds
- Security: inherits Ethereum network security
- Transparency: every transaction is publicly verifiable on Polygonscan
- Durability: decentralized network, no single point of failure
What HugCert proves
- Existence: this message existed on this precise date (blockchain timestamp)
- Integrity: the message has never been modified since certification (hash verification)
- Priority: the hash was recorded before any possible dispute (proof of anteriority)
HugCert vs other certification methods: comparison
| Method | Proof of existence | Proof of integrity | Publicly verifiable | Cost | Speed |
|---|---|---|---|---|---|
| Registered mail | Yes | No | No | €5-10 | Days |
| Notarized act | Yes | Yes | No | €100-300 | Weeks |
| Server timestamp | Yes | Partial | No | Free | Instant |
| NFT (Ethereum) | Yes | Yes | Yes | €10-50 | Minutes |
| HugCert (Polygon) | Yes | Yes | Yes | €2.99 | Seconds |
HugCert pricing
- €2.99 per certified Hugz
- 3 certifications included with the Hug Eternal plan (€4.99/month)
Certification is permanent and irreversible. Your PDF certificate is downloadable at any time, and the transaction remains verifiable indefinitely on Polygonscan.
Frequently asked questions about HugCert
What is a SHA-256 hash?
SHA-256 is a cryptographic algorithm that transforms any content (text, image, video) into a unique 64-character hexadecimal string. The slightest modification to the original content produces a completely different hash, making any tampering detectable.
Does HugCert have legal value?
Blockchain timestamping constitutes proof of anteriority recognized in many jurisdictions. The PDF certificate with hash, transaction, and QR code can serve as supporting evidence. For formal legal value, it can be coupled with a bailiff's report if needed.
Can I verify a HugCert certificate myself?
Yes. The PDF certificate contains the Polygon transaction ID and a QR code. You can verify the transaction on Polygonscan and recalculate the message hash to confirm it matches the one recorded on-chain.
What happens if I modify my Hugz after certification?
The certificate refers to the content at the time of certification. If you modify the message, the hash will no longer match. You can certify the new version, but the old certification remains valid for the original content.
Does HugCert work with all message types?
Yes. HugCert can certify any Hugz: text, photo, video, or audio. The hash is calculated on the entire message content, including media.
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