Government & Critical National Infrastructure

The NSA: The White House mandated use of symmetric encryption in 2022  which directs National Security Systems (NSS) to use symmetric keys.

The NSA published a statement via NIAP in August 2023 which mandates the use of RFC8784 by all VPN vendors selling under NSA CSfC authority . RFC8784 is the IETF standard which describes how symmetric keys must be injected into networking appliances like VPNs. NSA CSfC/NIAP is therefore demanding that all classified user VPNs use symmetric keys using this standard. Arqit is the only cloud-software-fulfilled method of delivering symmetric keys which allows true RFC8784 compliance. The only other secure way to inject symmetric keys into appliances using this standard is to use a hardware crypto device, which is cumbersome and expensive and does not allow dynamic creation of multi-cloud connections wherever you want them.

A joint paper  was issued on 26 January 2024. It is a relatively high level paper on the perceived constraints and issues on use of QKD. The paper also contains statements about symmetric encryption:

• “In light of the urgent need to stop relying only on quantum-vulnerable public-key cryptography for key establishment, the clear priorities should therefore be the migration to post-quantum cryptography and/or the adoption of symmetric keying “.
• “Post-quantum cryptography and symmetric keying (with pre-shared symmetric keys) must be the primary solutions for quantum-safe cryptography.”

ANSSI: The December 2023 paper by ANSSI recommends hybrid methods for authentication and encryption

• "ANSSI encourages all industries to define a progressive transition strategy towards quantum-resistant cryptography for relevant cryptographic products. The use of hybrid post-quantum mitigation is recommended especially for security products aimed at offering a long-lasting protection of information (until after 2030) or that will potentially be used after 2030 without updates."
• “While there is no concrete evidence that symmetric cryptographic mechanisms would be significantly threatened by quantum computers, a speedup can be expected in certain cases with Grover algorithm and other advanced Grover-based algorithms. Thus, as a conservative measure, ANSSI also encourages to dimension the parameters of symmetric primitives as to ensure a conjectured post-quantum security – in practice at least the same security level as AES-256 for block ciphers and at least the same security level as SHA2-384 for hash functions. This encouragement is slightly more conservative than NIST's and BSI's current recommendation.”

BSI: The BSI recently published a report  stating PQCs are not going to help to mitigate the quantum threat in time.

• “On average, this means the participating organisations expect to complete the migration to quantum-safe cryptography 6.5 years too late. If confidential information can be read for many years, possibly while going unnoticed, this could have serious consequences.”