OpenAI and Over 100 Companies Release Open Letter on AI Cyber Defense

OpenAI has released an open letter jointly signed by over 100 companies including Microsoft, Google, Anthropic, Deutsche Telekom, and SAP regarding cyber defense powered by AI. The letter warns that AI-enabled attacks on critical infrastructure such as hospitals and water treatment facilities are becoming increasingly sophisticated, and calls for swift action while the defensive side still maintains an advantage.

Cyberattacks on critical infrastructure have long been a concern for international security, but in recent years there has been growing consensus that AI proliferation is increasing both the precision and scale of attacks. Since AI can become a powerful tool for malicious actors as well, experts have pointed out that it could be used for the "automation and efficiency" of attacks, such as automating phishing fraud and discovering system vulnerabilities. This open letter can be seen as evidence that such concerns are being shared across the tech industry.

The companies that signed the letter span a wide range, from cloud and AI infrastructure providers to major telecommunications and enterprise software firms. Notably, core generative AI companies OpenAI, Google, and Anthropic have all signed, demonstrating collaboration that transcends competitive relationships within the industry. The participation of major European companies such as Deutsche Telekom and SAP also indicates that this concern extends beyond North America.

The letter specifically highlighted hospitals and water treatment facilities as targets. These are critical infrastructures that have long been considered vulnerable to attacks, as service disruptions directly threaten human lives while security investments often lag behind those of private companies. If AI-enabled attacks target such facilities, the speed and scale of damage could enter an unprecedented phase.

The significance of this initiative goes beyond a mere cross-industry "statement." A joint signature from over 100 companies can serve as pressure on policymakers and regulators to take action as the collective will of the industry. The letter's emphasis on the time axis—"while the defensive side still maintains an advantage"—can be understood as a clear message that postponement of countermeasures will not be tolerated.

A key point to watch going forward is whether this open letter leads to concrete policy or industry standard development. The implementation of defense measures by each signatory company in their respective products and services is also a matter to be scrutinized. Since there is always a gap between issuing a statement and actually taking action, there is a view that continuous monitoring of each company's efforts is necessary.