Japan Airlines has warned roughly 92,000 customers that hackers accessed their personal information through a third-party reservation plat...
The research was conducted by Google DeepMind in collaboration with cryptography researchers from the University of California San Diego and Inria.
RSA is a widely used public-key cryptographic algorithm that relies on the mathematical difficulty of factoring large numbers. Although RSA-1024 was once considered sufficiently secure, advances in computing and cryptanalysis have made it unsuitable for protecting sensitive information. Modern systems generally use RSA keys of 2048 bits or longer.
The first major finding focused on digital signature forgery involving the PKCS#1 v1.5 padding format. Padding is additional data inserted into a message before signing to ensure that it meets the required block size. Researchers examined how this protection behaves when an attacker can influence the content of the message being signed.
The team found that when an attacker controls approximately half or more of the signed data block, the padding may no longer provide additional protection against forgery. This weakness is relevant to the PKCS#11 signing interface used by cryptographic devices, including hardware security modules.
To show the improvement, DeepMind's AI agents reproduced an earlier academic signature-forgery attack against an RSA-1024 key. The agents reduced the required computing time from approximately 1,380 CPU core-years to 391 CPU core-years, making the process around 3.5 times more efficient.
Two AI agents reportedly designed, executed and debugged the computation in less than four days, with approximately 20 messages from a human researcher, most of which involved approving their actions.
Researchers also developed a more efficient approach for situations where attackers control a smaller portion of the signed message, such as a 32-byte hash. Their theoretical calculations suggest that the proposed method could be approximately 1,600 times more efficient than the previous best approach for certain RSA-1024 signature-forgery scenarios.
The second major finding concerns RSA key factoring. RSA security depends on the difficulty of breaking down a large number into its original prime factors. The researchers developed an algorithm that could make factoring each additional RSA-1024 key approximately 30 times cheaper on average after an expensive initial computation.
However, this technique remains theoretical and has not yet been implemented. The initial computation would also require substantial resources, meaning the findings do not show an immediate practical attack against deployed encryption systems.
The researchers also highlighted important limitations of the signature-forgery technique. It requires approximately four billion signing queries in advance, does not recover the private key and does not work against devices that internally hash messages before signing.
According to Pushmeet Kohli, Vice President at Google DeepMind and Chief Scientist at Google Cloud, modern cryptographic protocols generally use RSA keys of 2048 bits or larger and remain secure against the demonstrated techniques.
Iris Ohyama, one of Japan's most recognized consumer goods manufacturers, has disclosed that a third-party cloud service used by its online shopping platform was accessed without authorization, potentially exposing personal data belonging to roughly 7.7 million people, including customers who never created an account.
The company, founded in 1971 and headquartered in Sendai, is best known for plastic storage solutions and home appliances sold across Asia, Europe, and North America. Its e-commerce platform, Iris Plaza, caters to millions of customers in Japan and handles a large volume of household product purchases. The scale of the breach puts it among the larger data security incidents Japan has seen this year, in a period when Japanese companies and government agencies have dealt with a string of serious intrusions.
How the Breach Was Detected
On October 28, 2026, Iris Ohyama staff detected suspicious files inside a cloud service that Iris Plaza relies on for its operations. The company did not name the cloud provider or describe the method the attacker used to get in. Within a day, the company suspended access to Iris Plaza and related systems, reported the incident to Japan's Personal Information Protection Commission, and filed a report with police.
A follow-up disclosure on November 5 gave a clearer picture of the scope: up to 5.8 million registered and former members may have had their data accessed, along with up to 1.9 million non-members, meaning people who had completed a guest checkout without registering. The fact that guest buyers are part of the exposure is insurmountable, since many people assume their data is not retained when they shop without creating an account. In Iris Plaza's case, it was.
What Data Was in the Affected System
The range of information potentially accessed varies depending on the type of account. For registered members, exposed fields can include full name, home address, phone number, email address, gender, and date of birth. Account passwords were also stored in the affected environment, though the company said they were encrypted. It did not specify which encryption method was used, leaving questions open about how resistant those passwords are to cracking.
Former members are in a slightly different position: Iris Ohyama said it does not retain passwords for accounts that have been closed, so that group faces a narrower exposure. For non-members who checked out as guests, the data stored was more limited.
One notable reassurance: the company confirmed that credit card information was not stored in the affected cloud environment, sparing customers from the most immediately damaging form of financial exposure.
As of November 5, Iris Ohyama said it had not received any communication from whoever carried out the intrusion, had not identified any perpetrators, and had not seen reports of fraudulent use or financial damage tied to the breach. The investigation into how many records were actually exfiltrated, as opposed to merely accessible, is still ongoing.
What Iris Plaza Customers Should Do Now
The company has urged customers to change their Iris Plaza passwords and, critically, to change passwords on any other service where they used the same credentials. Password reuse across sites remains one of the most common ways a single breach cascades into wider account takeovers. Anyone who shops with the same email and password combination across multiple retail or financial platforms is at elevated risk.
Iris Ohyama also warned customers to be on guard for phishing attempts. With names, addresses, phone numbers, and email addresses potentially in circulation, attackers have enough to craft convincing messages that appear to come from the company. Iris Ohyama said it will not send emails or SMS messages asking for passwords, PINs, authentication codes, or other sensitive information through links, and customers should treat any such request as fraudulent.
A Year of Costly Data Incidents in Japan
The Iris Ohyama breach lands in the middle of a rough stretch for data security in Japan. This year alone, cloud hosting provider Sakura Internet reported a hack affecting up to 1.36 million accounts, telecommunications giant KDDI disclosed a breach tied to a zero-day vulnerability in third-party software that hit around 12 million accounts across shared email platforms, and Japan's Digital Agency acknowledged that a VPN flaw exposed approximately 246,000 government personnel records. The common thread across several of these incidents is reliance on third-party services and cloud environments where access controls or vendor security fell short.
Iris Ohyama's breach fits that pattern. A third-party cloud provider, an intrusion the retailer only caught when suspicious files turned up, and millions of customer records sitting in an environment the company did not fully control. The investigation remains open, and the company has not said when it expects to restore Iris Plaza to service.