Frequently asked questions about CardProof
CardProof is a neutral proof-of-possession service for physical collectibles. We help collectors create verifiable records that prove they possessed a specific item at a specific point in time. This is not proof of ownership or authenticity—it's proof of possession.
CardProof currently supports trading cards (sports, TCG, non-sports), sealed products, memorabilia, and other collectibles. We're expanding to support additional categories based on user demand.
Creating an account is free. Each proof you create is a one-time $5 charge—there's no subscription and no monthly fees. You only pay for the proofs you make.
CardProof pairs a timed capture process with cryptographic safeguards. When you begin, we issue a unique, single-use verification code and give you a 90-second window to photograph your item from multiple angles alongside that code written in your own hand. Our system then uses AI vision to automatically read your handwritten code and confirm it matches the one issued for that session—so the photos could only have been taken for this specific proof. Each image is run through SHA-256 to generate a tamper-evident digital fingerprint, and your account, the verification code, the exact timestamp, and every image's fingerprint are cryptographically bound together into a single sealed session hash. The result is a time-stamped, tamper-evident record: if any image, code, or timestamp is altered after the fact, the cryptographic seal no longer matches—providing strong, verifiable evidence that you physically possessed that specific item at that specific moment.
The handwritten verification code prevents the use of pre-existing photos or digital manipulation. Each code is unique and expires after use, ensuring the photos were taken specifically for this verification session.
The capture session has a 90-second time limit to ensure all photos are taken in immediate succession, reducing the possibility of switching items between shots. This tight window reinforces the authenticity of the proof.
No. CardProof is strictly a proof-of-possession service. We do not verify authenticity, grade condition, or assess value. For graded items, we record the existing certification information but do not validate it.
Yes. Proofs can be transferred to other CardProof users. The transfer records are permanently logged in the proof's history. You can optionally require the recipient to capture new photos to complete the transfer.
When you sell a verified item, you can transfer the proof to the buyer. The proof history will show the transfer, maintaining a complete chain of custody. The buyer can then create their own fresh proof if desired.
You control the visibility of each proof. Public proofs are viewable by anyone with the link. Unlisted proofs are only accessible via direct link. Private proofs are visible only to you. You can change visibility at any time.
We collect the information you provide (email, username, item details) and the photos you upload during verification. We do not sell your data to third parties. See our Privacy Policy for complete details.
Yes. You can export all your data at any time (GDPR compliance) and permanently delete your account. Note that deleting your account will revoke all your proofs.
Trust Levels (L1-L3) indicate how thoroughly a holder's identity has been verified, and appear as a badge on their proofs so viewers have added confidence in who created the record. Level 1 reflects a verified email address; higher levels represent additional identity verification. Your Trust Level is purely an identity-assurance signal—it does not limit how many proofs you can create or restrict your account in any way.
Proof Freshness indicates how recently the proof was created. Fresh proofs (< 7 days) are considered most reliable for current possession. Older proofs still prove historical possession but may not reflect current status.
Yes. All images are stored securely using industry-standard encryption. Images are processed to generate file hashes that can be used to verify the images haven't been tampered with after upload.