Censys vs dead-drop

Censys grew out of the University of Michigan's ZMap internet-scanning research and now re-scans the full public IPv4 space multiple times a day, fingerprinting open ports, services, and TLS certificates. Its Search API exposes that host and certificate-transparency dataset for asset discovery, exposure monitoring, and threat hunting, and underpins Censys's own attack-surface-management product. Access is account-scoped through an API key, with a limited free community tier and metered paid plans for higher query volume.

dead-drop is a minimal, self-hostable API for sharing ephemeral secrets: the client encrypts the payload before it ever reaches the server, so the backend only ever stores ciphertext it cannot read, and each secret can be set to self-destruct after a single view or a time limit. It needs no account or API key — requests are simply rate-limited per IP — and returns plain JSON over a small REST surface. The design mirrors the classic one-time-secret pattern used for sharing passwords or tokens without leaving a permanent copy anywhere.