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Prove a file existed with quantum-resistant dual signatures (ECDSA P-256 + NIST-standardized ML-DSA-65). Hash locally (SHA-256), dual-sign ledger entries, anchor to Bitcoin via OpenTimestamps. First known publicly accessible (as of October 2025) quantum-resistant timestamping service.
SasaSavic Quantum Shield™Quantum-secure timestamping for verifiable digital proofs
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Traditional cryptographic timestamping services rely on elliptic curve cryptography (ECDSA, EdDSA) or RSA signatures to prove the authenticity of timestamped ledgers. However, these algorithms are vulnerable to quantum computer attacks using Shor's algorithm, which can break these cryptosystems in polynomial time once sufficiently powerful quantum computers exist. The cryptographic community...
SasaSavic Quantum Shield™Quantum-secure timestamping for verifiable digital proofs