Arqit is a cybersecurity company that develops and delivers quantum-resistant encryption software through its SKA-Platform (Symmetric Key Agreement Platform). The company focuses on protecting organizations against both current cryptographic vulnerabilities and future quantum computing threats by eliminating reliance on traditional Public Key Infrastructure (PKI). Arqit's core product is a software-only, cloud-based key agreement platform that provisions, authenticates, and distributes quantum-safe symmetric encryption keys to endpoints. The platform operates through lightweight virtual agents installed on endpoints, which communicate with Arqit's multi-tenanted cloud infrastructure to generate and agree on session encryption keys without transmitting those keys over the network. This split-trust cloud architecture is central to their security model. The platform supports deployment as either a Private Instance (PI) or as a Platform as a Service (PaaS), and is compliant with NIST, FIPS 140-3, ISO 27001, and ISO/IEC 11770-2.2018 standards. Its protocols have been formally verified using the Tamarin prover method by the Surrey Centre for Cyber Security. Arqit targets enterprise and government customers and integrates with existing OEM infrastructures including VPNs, firewalls, cloud providers, IoT devices, telcos, and networks. The platform supports cryptographic agility, meaning it can adapt to evolving algorithms and standards without requiring changes to underlying infrastructure. It also provides centralized policy management and endpoint group controls. The company positions its approach as a complement to post-quantum algorithms (PQAs), with customers able to opt for symmetric-only key provisioning, not requiring PQAs at all.