Researchers, journalists, and legal professionals often need to prove when specific web content existed. Current tools for timestamping are either too technical or unreliable.
Build a simple web service where users can enter a URL and receive a cryptographic timestamp proving the page's existence at that moment. Use blockchain or other immutable ledgers for verification.
Charge enterprise users like law firms and newsrooms for bulk timestamping and verification services. Offer a free tier for individual researchers.
Start with a basic web interface that timestamps URLs and generates verifiable proofs. Later add browser extensions and API access.
The biggest risk is competing with free but less reliable timestamping tools.