Verify a blockchain anchoring
OSCAR documents (rent receipts, leases, check-in reports and their photos, deeds, certificates…) are automatically timestamped on the Bitcoin blockchain through an open, standard protocol. This check works without an OSCAR account — for a future landlord, a bank, a court, or anyone else who receives such a document.
✅ What it proves
That the document (these exact bytes) already existed before its confirmation in the stated Bitcoin block — verifiable independently of OSCAR, with any standard blockchain verification tool.
❌ What it does not prove
It is not a qualified eIDAS electronic signature, and it proves neither the author's identity nor their consent to the content — only a date of existence. Details: legal value of signatures.
🔑 Check a future tenant's rent receipts
Ask the applicant for the PDFs of their last 3 OSCAR rent receipts (downloaded from their account, not reprinted or scanned) and drop them here one by one. A genuine receipt is recognised with its period; the slightest edit (amount, name, month) makes it unknown. This proves the receipt was really issued through OSCAR and has not been changed — the payment itself is declared by the landlord who issued it.
1. Choose the file to check
With the proof supplied with the document, the check runs entirely in your browser, without depending on OSCAR. You can also drop the ZIP of a report directly: it is opened on the spot.
2. Run the check
Choose a file first.
Your file is never sent to a server — only its fingerprint is computed in your browser.