Timestamping a giant record of the Web
Summary
Project Timestamper cryptographically timestamped the entire Common Crawl web page snapshot collection (339 billion snapshots, over 10 PB). Each snapshot’s hash is anchored to the Bitcoin blockchain, enabling verifiable proofs of existence as of 2026-09-26. The effort leverages batch hashing of 134 million blocks via OpenTimestamps and provides a CLI tool to verify individual snapshots.