IonQ on Monday said it signed a definitive agreement to buy Elisity in a stock-only transaction worth up to $1.3 billion.
Up to $150 million of that amount is earnout consideration, contingent on how Elisity’s business performs. IonQ expects to complete the acquisition in the fourth quarter of 2026.
The number of IonQ shares issued will depend on the company’s volume-weighted average price over 20 trading days ending shortly before closing, but the price will be kept between $33.07 and $49.61.
Founded in 2019, Elisity sells software that restricts which users, devices, workloads and AI agents can communicate on enterprise networks, based on least-privilege policies. A component called IdentityGraph combines what Elisity collects itself with data from partner tools, including identity, asset and risk details, to guide access decisions.
According to IonQ, Elisity has more than 100 customer deployments. The startup raised more than $70 million.
IonQ’s portfolio spans quantum computing, networking, sensing and security, and the company already offers post-quantum cryptography (PQC) and quantum key distribution (QKD). It plans to use Elisity’s customer and CISO relationships to reach more enterprise and government buyers for those technologies and its quantum computing products.
The two companies plan to add cryptographic inventory and risk data to IdentityGraph. The goal is to help organizations decide which post-quantum upgrades to tackle first, weighing business risk and the criticality of affected operations.
“Access controls reduce exposure; cryptographic upgrades would address the underlying weaknesses,” Elisity CEO James Winebrenner wrote in a blog post on the deal. In a press release, he noted: “Our customers need to prioritize post-quantum cryptography initiatives while securing existing assets to keep essential operations running.”
IonQ CEO Niccolo de Masi pointed to Q-Day, the point at which quantum computers could break widely used public-key encryption. “Q-Day is coming much faster than predicted,” he said. IonQ also cited recent White House executive orders promoting quantum technology and pushing federal agencies to adopt PQC sooner.
Once the deal is completed, Winebrenner and Elisity’s existing management team will remain in charge of the business.
SecurityWeek’s cybersecurity M&A tracker has cataloged roughly 300 deals to date in 2026.
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