Upload a file. Get a cryptographic timestamp from an independent authority. Reveal it later with proof.
Your file gets encrypted with XChaCha20-Poly1305 and timestamped by an independent authority via RFC 3161. You keep the only key.
The encrypted file is stored for 7 years. We can't read it — only you have the decryption key. Zero knowledge.
When you need proof, use your key to decrypt. Get your original file plus a court-ready evidence package — verifiable by anyone with OpenSSL.