Post-quantum VPNs resist attacks based on quantum computing and post-quantum cryptography (PQC). Palo Alto Networks post-quantum VPN support enables you to configure quantum-resistant IKEv2 VPNs and is based on the RFC 8784 standard to maximize interoperability with other vendors' equipment and with future standards. Multiple government agencies around the world, including the NSA and NIAP, recommend implementing RFC 8784 to improve quantum resistance. Implementing RFC 8784 is the simplest way to create quantum-resistant VPNs because you don't need to upgrade crypto elements.

Addressing the quantum threat immediately is critical to defend against Harvest Now, Decrypt Later attacks that target long-lived data because the development of cryptographically relevant quantum computers (CRQCs) will vastly reduce the amount of time required to break classical encryption.

Configuring quantum-resistant VPNs can prevent attackers from recording critical encrypted key material and thus prevent them from decrypting the data even if they steal it. If you have long-lived data, start planning now for the threat posed by quantum computers and quantum cryptography and for your network's transition to a post-quantum world. The first step is to make your VPN connections quantum-resistant.

RFC 8784 provides a transition from today's classical cryptography to PQC. Quantum-resistant VPNs based on RFC 8784 enable using post-quantum pre-shared keys (PPKs) that are not transmitted with the data, so harvesting attacks fail because they don't capture the key material that they need to decrypt the data later. A PPK is a complex, strong hexadecimal string that you statically program into the IKE peers at the ends of the VPN tunnel.

Adding a static PPK that's delivered out-of-band to the classical Diffie-Hellman (DH) key prevents Shor's algorithm from cracking the key because the key is no longer based on prime numbers. RFC 8784 enables using long, strong PPKs that meet the NIST Category 5 security level.

In addition, RFC 8784 provides the backward compatibility to fall back to classical cryptography if a peer can't support FRC 8784, so the implementation doesn't risk refusing legitimate connections. Palo Alto Networks implementation of RFC 8784 provides flexibility and quantum resistance for your IKEv2 VPNs:

In addition to implementing RFC 8784 now:

The following example topology shows three VPN termination sites. Sites A and C support post-quantum VPNs based on RFC 8784. Site B supports only classical VPNs. Site A must be able to communicate with both Site B and Site C.

Site A uses both Mandatory and Preferred negotiation modes. When Site A communicates with Site B, which only supports classical cryptography, Site A falls back to classical negotiation. When Site A communicates with Site C, Site A uses a PQ PPK because Site C supports using PQ PPKs.