Cloudflare has expanded its post-quantum security support to the connection between its global network and customer origin servers, giving website and application operators a new way to protect server authentication against future quantum-computing threats.
The company now accepts Module-Lattice-Based Digital Signature Algorithm, or ML-DSA, certificates for two origin-facing security features, Authenticated Origin Pulls and Custom Origin Trust Store. When configured with Cloudflare’s existing post-quantum key agreement, the update can protect both the confidentiality and authentication of traffic traveling between Cloudflare’s edge and an origin server.
Cloudflare documented the support in a June 17 product changelog and published a more detailed technical explanation on July 29, 2026. The change does not automatically make every Cloudflare-hosted website fully post-quantum secure. Customers must configure compatible certificates and origin-server software, and the feature currently focuses on the Cloudflare-to-origin portion of a connection.
What Cloudflare Changed
A website that uses Cloudflare typically involves two separate network connections.
The first runs from a visitor’s browser or application to Cloudflare’s network. The second runs from Cloudflare to the website owner’s origin server when Cloudflare needs to retrieve content or forward a request.
Cloudflare previously introduced post-quantum encryption for both parts of this path. Its latest work adds post-quantum authentication to the second connection, the link between Cloudflare and the customer’s origin infrastructure.
Authentication and encryption solve related but different problems.
Encryption prevents an unauthorized party from reading data in transit. Authentication confirms that the system at the other end of a connection is the system it claims to be. A future quantum computer capable of breaking widely used public-key algorithms could therefore create both confidentiality and impersonation risks.
Cloudflare’s update addresses the authentication side of that problem for origin connections.
How Authenticated Origin Pulls Use ML-DSA
Authenticated Origin Pulls, commonly abbreviated as AOP, allow an origin server to verify that an incoming request came through Cloudflare.
Without this protection, an attacker who discovers an origin server’s IP address may attempt to connect directly to it, bypassing Cloudflare’s firewall, caching, rate limiting, and other security controls.
With AOP enabled, Cloudflare presents a client certificate during a mutual TLS, or mTLS, handshake. The origin server checks that certificate before accepting the connection.
According to Cloudflare’s Authenticated Origin Pulls documentation, zone-level and per-hostname configurations can now use ML-DSA client certificates. These configurations allow customers to use certificates associated with their own account or hostname rather than relying only on Cloudflare’s globally shared certificate.
Cloudflare lists Authenticated Origin Pulls as available across its Free, Pro, Business, and Enterprise plans, although customers still need to configure their origin servers correctly.
What Custom Origin Trust Store Does
Custom Origin Trust Store handles the other side of the authentication relationship.
When Cloudflare connects to an origin server using Full (strict) encryption mode, it normally validates the server certificate against a collection of publicly trusted certificate authorities and Cloudflare’s Origin CA.
Custom Origin Trust Store allows a customer to replace that default trust store with certificate authorities the organization controls.
Cloudflare can now accept an ML-DSA certificate authority through this feature. The company then trusts origin certificates that chain back to the uploaded post-quantum CA.
Cloudflare’s Custom Origin Trust Store documentation says Advanced Certificate Manager must be enabled on a zone before the feature can be used.
Using Authenticated Origin Pulls and Custom Origin Trust Store together creates mutual authentication, the origin authenticates Cloudflare, while Cloudflare authenticates the origin.
Why Cloudflare Is Using ML-DSA
ML-DSA is a lattice-based digital-signature algorithm standardized by the US National Institute of Standards and Technology in Federal Information Processing Standard 204.
NIST finalized FIPS 204 in August 2024 as its primary post-quantum digital-signature standard. The agency describes ML-DSA as an algorithm designed to generate and verify digital signatures while remaining resistant to an adversary equipped with a sufficiently powerful quantum computer.
Cloudflare supports the three ML-DSA parameter sets specified by FIPS 204:
- ML-DSA-44
- ML-DSA-65
- ML-DSA-87
Each option offers a different balance of performance and security strength. Cloudflare recommends ML-DSA-44 for most applications because it has the lowest performance overhead among the three while still meeting NIST Category 2 security strength.
This does not mean ML-DSA is guaranteed to remain secure under every future discovery. Cryptographic standards continue to receive analysis, testing, and implementation updates. It does mean organizations now have a standardized option for beginning post-quantum authentication migrations.
Why Origin Authentication Matters for Businesses
Origin servers often contain the application logic, databases, administrative interfaces, and sensitive services behind a website. Protecting only the public-facing connection can leave an important part of the traffic path dependent on older authentication systems.
Post-quantum origin authentication may be particularly relevant to:
- Government agencies and contractors
- Financial institutions
- Healthcare and research organizations
- Critical-infrastructure operators
- Cloud and software providers
- Businesses retaining sensitive data for many years
The immediate concern is not that a publicly known quantum computer is already breaking modern TLS connections. The operational concern is that replacing cryptographic infrastructure across applications, servers, certificate systems, libraries, and organizational policies can take years.
NIST has encouraged organizations to begin preparing for post-quantum migration because large infrastructure transitions cannot be completed instantly.
Origin authentication is also only one part of infrastructure resilience. Businesses should combine cryptographic improvements with network redundancy, access controls, monitoring, and recovery planning. InfoSeely’s guide to dual WAN routers for small-business network stability explains how connectivity redundancy addresses a different part of the infrastructure-risk equation.
Deployment Requires More Than Enabling a Dashboard Setting
Cloudflare’s post-quantum origin support requires preparation on both sides of the connection.
Its technical walkthrough specifies OpenSSL 3.5.0 or later for generating the example ML-DSA certificate chains. Private keys must use the FIPS 204 seed-only encoding currently accepted by Cloudflare.
Administrators also need to:
- Generate and protect ML-DSA private keys
- Upload the appropriate CA or client certificate
- Configure Full or Full (strict) TLS mode as required
- Configure the origin server to validate the certificate
- Confirm that the TLS library supports ML-DSA
- Test the configuration before using it in production
- Monitor certificate validity and renewal dates
Cloudflare warns that uploading a custom CA replaces its default public trust store for that zone. If the uploaded CA expires without a valid alternative, Cloudflare may no longer be able to authenticate the origin server.
Organizations should therefore treat this as a controlled cryptographic migration, not a simple performance optimization.
The need to govern machine identities, credentials, and automated access is also increasing as companies deploy AI agents. InfoSeely’s coverage of the growth in MCP security infrastructure examines a related challenge, ensuring that automated systems receive only the permissions they need.
What the Update Does Not Cover
Cloudflare’s announcement should not be interpreted as universal post-quantum authentication for every public web connection.
The new certificate support applies to Cloudflare-to-origin traffic. Public browser authentication still depends on the broader web public-key infrastructure, certificate authorities, browser support, TLS libraries, and standards-development work.
An IETF working draft describes how ML-DSA may be negotiated for authentication in TLS 1.3, but an Internet-Draft is still a work in progress and can change before becoming a finalized standard.
Cloudflare is also working with Google and other organizations on Merkle Tree Certificates, a proposed approach to making post-quantum certificates more practical for the public web. Cloudflare says initial deployments are being targeted for 2027, but that timeline remains a company target rather than a guaranteed industry-wide rollout.
What Comes Next
Cloudflare has said it is targeting 2029 for full post-quantum security across its services. Supporting ML-DSA for origin authentication is an early milestone in that roadmap.
Broader adoption will depend on several developments:
- ML-DSA support becoming common in TLS and X.509 libraries
- Operating systems and server software receiving compatible updates
- Certificate-management tools supporting larger post-quantum keys and signatures
- Public certificate authorities developing deployment models
- Browsers and standards organizations agreeing on practical web-authentication approaches
- Organizations completing inventories of their existing cryptographic dependencies
For Cloudflare customers, the new support provides a production path for testing post-quantum authentication in an environment where Cloudflare and the customer control both ends of the origin connection.
Its wider significance is that post-quantum migration is moving beyond experimental encryption. Authentication, certificate management, server identity, and operational governance are becoming part of the same transition.
