Seal a file and it becomes opaque to everyone but you — the wrong key gives back nothing, the right key gives back your exact bytes. Use a file you don't mind picking; nothing leaves this page. The seal here is real AES-256-GCM. The part where the host is refused at the hardware is the substrate — the line is spelled out below.
The gate decides who may act. The substrate decides who can see.
The seal is genuine AES-256-GCM. The wrong key really recovers zero bytes (authentication fails), and the right key returns your file byte-for-byte — the SHA-256 match proves it. The ciphertext shown is the real sealed bytes.
The key is generated and lives inside the GPU — it never crosses to the host. And the host operating system is refused at the hardware: a read returns an I/O error, not data. Proven on two architectures — 99.98% Blackwell / 99.97% Lovelace.
Honest line: your browser holds this key in the page, so this shows you the seal's behavior, not sovereignty. The refusal-at-the-hardware — the part no browser can perform — is the substrate, and it is what Newtonian Standard licenses. This is not "encryption in a webpage"; it is the shape of the seal, with the machine property named for what it is.