OpenAI gives Japan's megabanks its newest model for cyber defence

GPT-5.5-Cyber will be delivered to MUFG, SMBC, and Mizuho through OpenAI’s Trusted Access for Cyber program. The arrangement limits access to vetted defenders because frontier models that can find vulnerabilities at scale can also enable misuse. The finance minister framed the model as critical national infrastructure rather than a consumer product. The collaboration involved direct engagement between Japan’s finance minister and the US Treasury secretary, giving it a government-to-government character. Japan is also building a broader public-private effort on AI-related cyber risk, involving major banks, the Bank of Japan, and leading AI labs, with additional frontier defensive access planned.

"GPT-5.5-Cyber will reach MUFG Bank, Sumitomo Mitsui Banking Corporation and Mizuho Bank through what OpenAI calls its “Trusted Access for Cyber” programme, a framework built to put the most capable tools only in the hands of verified defenders."

"The logic is gatekeeping: a model good enough to find vulnerabilities at scale is, by definition, dangerous if it reaches the wrong users, so access is rationed to institutions that can be vetted."

"Katayama and US Treasury Secretary Scott Bessent were directly involved in the discussions that opened the collaboration, lending it the character of a government-to-government understanding as much as a commercial supply deal."

"Japan established a public-private working group on AI-related cyber risk in the middle of May, drawing together the major banks, the Bank of Japan and the local units of the leading AI labs."

Read at TNW | Openai