Chugoku Electric Power adopts data protection and file transfer service f-FILTER
— Circumventing ZIP encryption through m-FILTER's email security features —

Information security solutions provider Digital Arts Inc. (headquarters: Chiyoda-ku, Tokyo, Japan; CEO: Toshio Dogu; hereinafter referred to as "Digital Arts"; Code 2326) is pleased to announce that The Chugoku Electric Power Co., Inc. (headquarters: Hiroshima City, Hiroshima Prefecture; President and CEO: Kengo Nakagawa) has decided to use the data protection and file transfer service f-FILTER. By integrating with the email security solution currently in use, m-FILTER, the company has been able to successfully implement systems that circumvent the traditional ZIP encryption methods often used in Japan.

f-FILTER and m-FILTER adopted by Chugoku Electric Power, a key infrastructure provider in the Chugoku region

Chugoku Electric Power, which operates an electric power business in Japan's Chugoku region, handles highly confidential information on a daily basis. Until now, the company has used a ZIP encryption (commonly known as PPAP) method to send files. However, due to concerns regarding leaks, the risk of attacks exploiting encrypted ZIP files, and the safety of recipients, it began to look at alternative methods.
Consequently, the company decided to adopt Digital Arts' f-FILTER service and integrate it with the previously implemented m-FILTER. This allowed the company to shift from ZIP encryption to a method that sends a download link.

The deciding factors for adoption included f-FILTER's high compatibility with the email security software m-FILTER, the ability to maintain the same file-sending process by simply attaching files to emails, and the enhanced security features, including restricting file viewers, checking access logs, and disabling access when needed. With this, the company has been able to improve the security of both emails and files.

ZIP-free security with the combined features of m-FILTER and f-FILTER

Through the integration of m-FILTER and f-FILTER, emails with attachments are automatically separated into the email body and the attached files, which are then transferred using online storage. Recipients can securely receive attachments without the need for passwords by authenticating their accounts via a download link automatically included in the email body. Access to files is restricted solely to email recipients, reducing the risk of unintended sharing with third parties, and even if an email is mistakenly sent to the wrong address, viewing permissions can be immediately revoked. Additionally, files sent can be scanned for malware before sending.

ZIP encryption (PPAP) continues to pose security challenges in Japan

Sending files via ZIP encryption has long been the standard method in Japan. However, due to growing concerns, including those outlined above, more companies are beginning to consider other methods. In a survey*1 conducted by Digital Arts on approximately 2,000 organizations in Japan, it was revealed that many still send ZIP-encrypted files. It was also found that business partners receiving those files were still largely expected to accept them without question, showing that the practice remains deeply rooted.

As a comprehensive security solutions provider, we at Digital Arts are committed to protecting businesses from all forms of cyber risks, including moving away from the PPAP method, and continue to enhance features and develop new products to support that mission. Digital Arts will support the implementation and operation of its solutions at Chugoku Electric Power on an ongoing basis, while actively promoting the broader adoption of ZIP-free file transfer methods across enterprises.

*1: Published on January 29, 2025 — "Analysis of email attachments in Japan: ZIP file usage halved since five years ago, yet over 6,000 domains still used password-protected ZIPs during two-week survey period"