QuantumStamp incorporates quantum-resistant timestamps into iPhones. Important files are only calculated with SHA-256 fingerprint on the device itself, then submitted to the public testing interface of SasaSavic Quantum Shield. It is double-signed by ECDSA P-256 and NIST standardized ML-DSA-65, and anchored by OpenTimestamps to Bitcoin. The original files do not leave the phone and are suitable for those who need to prove that a certain work, research record, or technical document existed on a specific date. The application will save local certificates, verify the hash against the public ledger, and display the daily ledger and the signature public key. The timestamp service itself does not require an account; Proof Vault is used to save more annotated proofs on the device.
