4 services carry this tag in their source record. Tags come from the provider, not from us — a tag is a claim about what the service does, not proof that it does it well.
Timestamp SHA-256 hashes in Bitcoin with OpenTimestamps: returns a standard .ots proof per hash (pending, complete within hours), verifiable without us
Timestamp anything on Bitcoin with OpenTimestamps: send text, a SHA-256 hash or a URL and get a standard .ots proof (base64). Only a salted hash leaves our server. The public calendars anchor it in a Bitcoin block within...
Verify an OpenTimestamps proof (.ots as base64, from btc-timestamp or any ots client): upgrades pending proofs from the calendars, checks each Bitcoin attestation against the real block's merkle root and returns status (...
Breached password check: is this password in known data breaches, and how often? Send only the SHA-1 hash (never the password); just the first 5 characters reach Have I Been Pwned (k-anonymity). Up to 50 hashes per call.