How your certificate is kept
Every ChainChum certificate is recorded on Base, a public blockchain. Here's the contract, who can change what, and what stays private.
Source verifiedOn-chain issuing is live
The contract
- Network
- Base (chain 8453)
- Certificate contract
- 0x14f5…3DE8
- Code it runs
- 0x582a…433c
- Live since
- November 12, 2026
Who can do what
- Issue, move to a buyer, voidChainChum's issuing key, and only when our records change: a sale, a refund, a gift or a correction.
- Pause, change the link, upgrade the codeA separate admin key. Every upgrade is public on Basescan, and past records can't be rewritten.
- Sell or send a certificate elsewhereNobody, for now. Certificates stay with their holder on ChainChum until wallet export arrives.
What's public, what's private
On the blockchain, for good
- The token number
- A fingerprint (hash) of the certificate's record
- Pseudonymous addresses for the artist and the holder
- Whether it was voided
Never on the blockchain
- Names and email addresses
- Home and shipping addresses
- Prices and payment details
- Anything about a child
These addresses can't be traced back to you: each one is derived from your account with a private salt and has no key, so no one can take a certificate out of your account.
The record behind the fingerprint (the work's title, the artist's shop, medium, size and edition) is shown on each certificate's page. A collector's name appears there only if they choose to show it.
Keys and safeguards
- Both keys live in a hardware security module and never leave it. Creating one takes two people.
- Any use of the admin key raises an alert to the team.
Check it yourself
- Open a certificate at chainchum.app/c/ followed by its code.
- Its page recomputes the fingerprint from the record and compares it with the blockchain.
- On Basescan, Read as Proxy › contentHashOf(token) shows the same value.