Google on Friday unveiled its plan for its Chrome browser to secure HTTPS certificates against quantum computer attacks without breaking the Internet.

The objective is a tall order. The quantum-resistant cryptographic data needed to transparently publish TLS certificates is roughly 40 times bigger than the classical cryptographic material used today. A typical X.509 certificate chain used today comprises six elliptic curve signatures and two EC public keys, each of them only 64 bytes. This material can be cracked through the quantum-enabled Shor’s algorithm. The full chain is roughly 4 kilobytes. All this data must be transmitted when a browser connects to a site.

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“The bigger you make the certificate, the slower the handshake and the more people you leave behind,” said Bas Westerbaan, principal research engineer at Cloudflare, which is partnering with Google on the transition. “Our problem is we don’t want to leave people behind in this transition.” Speaking to Ars, he said that people will likely disable the new encryption if it slows their browsing. He added that the massive size increase can also degrade “middle boxes,” which sit between browsers and the final site.

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Merkle Tree Certificates, “replace the heavy, serialized chain of signatures found in traditional PKI with compact Merkle Tree proofs,” members of Google’s Chrome Secure Web and Networking Team wrote Friday. “In this model, a Certification Authority (CA) signs a single ‘Tree Head’ representing potentially millions of certificates, and the ‘certificate’ sent to the browser is merely a lightweight proof of inclusion in that tree.”

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The new system has already been implemented in Chrome. For the time being, Cloudflare is enrolling roughly 1,000 TLS certificates to test how well the MTCs work. For now, Cloudflare is generating the distributed ledger. The plan is for CAs to eventually fill that role. The Internet Engineering Task Force standards body has recently formed a working group called the PKI, Logs, And Tree Signatures, which is coordinating with other key players to develop a long-term solution.