Show HN: Free Quantum-Resistant Timestamping API (Dual-Signature and Bitcoin) https://ift.tt/7sYOqtC

Show HN: Free Quantum-Resistant Timestamping API (Dual-Signature and Bitcoin) SasaSavic.ca recently launched a public cryptographic timestamping service designed to remain verifiable even in a post-quantum world. The platform uses SasaSavic Quantum Shield™, a dual-signature protocol combining classical and post-quantum security. Each submitted SHA-256 hash is: • Dual-signed with ECDSA P-256 and ML-DSA-65 (per NIST FIPS 204) • Anchored to the Bitcoin blockchain via OpenTimestamps • Recorded in a public, verifiable daily ledger API (beta, no auth required): https://ift.tt/4wVpEq2 Example curl request: curl -X POST https://ift.tt/KGz62bI -H "Content-Type: application/json" -d '{"hash":"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"}' Verification and ledgers: https://ift.tt/RysNpVQ https://ift.tt/YRrq2Jo The goal is to make cryptographic proofs quantum-resistant and accessible, while preserving user privacy — only the hash ever leaves the client side. Feedback from developers, auditors, and researchers on PQC integration and verification speed is welcome. More details and documentation: https://ift.tt/n7Kqxb3 – The SasaSavic.ca Team November 5, 2025 at 01:51AM