Headline Recorder signs every article and op-ed it publishes with a hybrid post-quantum signature, ML-DSA-87 (FIPS 204) composed with Ed448 (RFC 8032), over a canonical encoding of the stored article and its metadata. Signatures are detached, published at stable addresses and verifiable by anyone in a browser, against a public keyset signed by an offline key whose identifier is published in DNS. Contributor submissions are sealed in the browser with a hybrid ML-KEM-1024 + P-384 key encapsulation feeding AES-256-GCM.
This white paper covers the threat model, cryptographic design and parameters, the pure-PHP implementation and its validation against NIST ACVP vectors, key management, the signing pipeline, limitations and how to verify an article yourself.