The integrity of blockchain will face enormous challenges in the AI and quantum eras. The threat of quantum mechanics is not far off, which is the significance of projects like bb84. bb84 is a post-quantum security infrastructure project built for Solana. bb84 brings post-quantum protection to the application layer, and it's available today: A real QPU is responsible for seeding keys and generating random numbers, recording job receipts on the blockchain, and the Solana program performs verification. Users use Falcon-512 signatures. Public keys are registered only once, and every subsequent transaction only includes a signature. The Q-Day switch is irreversible: once enabled, even if the classic private key is stolen, funds can only be moved via Falcon. No protocol modifications are required. Already running on devnet. https://bb84.sh