Quantum Shield
First known publicly accessible quantum-resistant timestamping. Dual-signature proofs anchored to Bitcoin—verifiable even against future quantum computers.
What it does
SasaSavic Quantum Shield™ creates verifiable proof-of-existence timestamps using dual cryptographic signatures: classical ECDSA P-256 and NIST-standardized ML-DSA-65 (quantum-resistant). Proofs are anchored to the Bitcoin blockchain via OpenTimestamps for independently verifiable time evidence.
How it works
- 1.Local fingerprint — SHA-256 hash computed in your browser. Files never leave your device.
- 2.Dual signatures — ECDSA P-256 (classical) + ML-DSA-65 (quantum-resistant) applied to the ledger.
- 3.Bitcoin anchor — Dual-signed ledger anchored to Bitcoin blockchain via OpenTimestamps.
- 4.Quantum-resistant verification — Anyone can verify both signatures independently.
Key properties
- •100% private — Files never leave your device; only the hash is submitted
- •Future-proof — ML-DSA-65 protects against quantum computer attacks
- •Open verification — Independent proof verification without our involvement
Who it's for
- ○Researchers — Timestamp findings before publication to establish priority
- ○Creators — Prove ownership of creative work with verifiable timestamps
- ○Engineers — Timestamp code commits and architecture documents
- ○Law & Compliance — Cryptographic proof for legal records and contracts
Current status
SasaSavic Quantum Shield™ launched in October 2025 as the first known publicly accessible implementation of dual-signature timestamping for quantum-resistant protection. The service is live and operational.