Quantum platform and foundry IonQ (NYSE:IONQ) announced on Monday that it has signed a definitive agreement to acquire cybersecurity company Elisity Inc in an all-stock transaction valued at up to USD1.3bn, including up to USD150m in performance-based earnouts.

The deal combines IonQ's post-quantum cryptography and quantum key distribution capabilities with Elisity's Zero Trust security platform to address existing cyber threats and prepare enterprise and government customers for quantum-era risks.

Elisity brings more than 100 global customer deployments, established relationships with chief information security officers, and a recurring-revenue business that has doubled revenue and its customer base year over year, with no churn among deployed customers, according to IonQ. The acquisition also positions IonQ to pursue opportunities in the microsegmentation market, which the company estimates exceeds USD10bn and is growing at a double-digit compound annual growth rate.

The combined platform is expected to integrate cryptographic risk intelligence with identity-based access controls, strengthening defences against current cyberattacks, including threats involving AI agents, and emerging quantum risks. IonQ expects to expand cross-selling opportunities and develop integrated security offerings for enterprise and government customers.

Elisity will continue operating under its existing leadership, including CEO James Winebrenner.

Subject to customary closing conditions, including regulatory approval, the acquisition is expected to close in the fourth quarter of 2026.