Quantum computing

BIS Innovation Hub, Inter-American Development Bank, Central Bank of Chile, Bank of Canada

The project separated cryptographic functions into dedicated microservices so that security functions could be upgraded or scaled without redesigning the full settlement engine. It used a hybrid cryptographic design: traditional cryptography remained in place for encryption and decryption, while post-quantum cryptography was tested for digital signature verification and signing, i.e. the functions that confirm message authenticity and integrity. The post-quantum signature approach was based on CRYSTALS / Dilithium, referred to in the report as ML-DSA under NIST FIPS 204.

The project demonstrated that a modular, microservices-based settlement engine could support scalability, flexibility and quantum-resistant security under controlled test conditions. The proof of concept reached 10,000 transactions per second, scaling from 2,500 to 10,000 TPS without an equivalent increase in computing resources or infrastructure cost, while allowing additional capacity to be directed to resource intensive cryptographic services. It also showed that cryptographic functions could be isolated, scaled and updated independently, but highlighted trade-offs around orchestration, monitoring, inter-service dependencies, attack surface and the need for further resilience, security, regulatory and real-world testing before any production use.

BIS Innovation Hub Eurosystem Centre, Bank of Italy, Bank of France, Deutsche Bundesbank, Nexi-Colt, SWIFT

The experiment focused on the digital signature attached to the business application header of T2 payment messages - the part used to confirm who sent the message and whether it was altered. The current RSA-based signature at this level was replaced with a post-quantum CRYSTALS-Dilithium signature using NIST security strength category 3. A new post-quantum cryptography signature-verification component was added alongside the existing traditional signature-verification software, allowing valid post-quantum-cryptography signed inbound messages to be processed and invalid ones to be rejected. The broader configuration preserved compatibility with existing operations: the outbound flow remained signed with traditional RSA, while the post-quantum cryptography test setup relied on software-based key files / raw key pairs rather than a physical HSM or conventional digital certificate validation.

The project confirmed that post-quantum signatures could be implemented in a T2 test payment-system environment while preserving the system’s core acceptance and rejection logic. Liquidity transfer messages with valid post-quantum signatures were successfully processed and validated, while messages signed with an incorrect post-quantum private key were rejected with the expected error response; interoperability between participants using different post-quantum solutions was also verified. The experiment also identified migration constraints, including materially higher post-quantum signature-verification times, the need for further testing with certificates and HSMs, substantial system evolution to support hybrid cryptographic protocols, and coordinated planning across central banks, network service providers and vendors.

Bank of France, Allianz France

The project used an encapsulation-based hybrid TLS design: instead of modifying OneGate, the IAM system or the client applications, it placed a quantum-safe TLS layer around existing TLS communications. For browser access, the Bank of France deployed an NGINX HTTP reverse proxy in front of OneGate/IAM to support hybrid x25519 + ML-KEM key exchange while keeping RSA certificates for client and server authentication. For non-updatable browsers or applications, Allianz France used a Stunnel forward proxy and the Bank of France used an NGINX stream reverse proxy to create a quantum-safe TLS tunnel between the two organisations; the tunnel used hybrid key exchange / key encapsulation and ML-DSA certificates for mutual authentication, while the internal application flow continued to use standard TLS. Because the existing corporate PKI did not support post-quantum cryptography, the project also deployed a CNS-supported EJBCA CE post-quantum cryptography PKI to generate an ML-DSA87 certificate authority, server certificate and client certificate.

experiment demonstrated that quantum-safe protections can be added to existing regulatory file-transfer channels without modifying OneGate, IAM or core application logic. The test set-up showed that post-quantum TLS tunnels can secure file transfers while preserving operational continuity, with negligible network latency, only a minor and acceptable impact on TLS handshake time, and unaffected data transfer performance. It also identified practical migration limits in legacy proxies, TLS interception, PKI and client-side support for post-quantum certificates, while concluding that phased implementation is feasible, can protect sensitive data flows today, and provides a reusable pattern for broader post-quantum migration.