Friday 26 September, 2025
SMS phishing (smishing) attacks are increasingly difficult for customers to identify because standard SMS only displays a phone number or alphanumeric sender ID, making it hard to tell if a message is genuine from an official source. Existing network-level and device-side spam filters reduce but do not eliminate these threats, creating a need for stronger, low-cost, app-level measures to clearly distinguish legitimate corporate messages and improve customer trust.
KDDI collaborates with the MIC (Ministry of Internal Affairs and Communications) to leverage RCS for combating SMS phishing by displaying official logos and verification marks, enhancing customer trust. The RCS messaging application, OS native apps or “Plus Message Service” app. in Japan allows for clear identification of legitimate messages, significantly improving security. Network-level spam filtering and free device filtering further reduce threats, but app-side measures like verified markings are recommended for optimal safety at low cost.
Solution
- Collaboration with the MIC and financial industry to develop app-level countermeasures to SMS phishing.
- Leveraging RCS (OS native apps or “Plus Message” service) to send messages with company logos and verified marks.
- Clearly distinguishing official corporate accounts with verified marks within the RCS app interface so customers can recognize legitimate messages.
- Prior screening of companies using the RCS service by auditing and verification performed by telecom carriers to ensure only verified businesses send messages.
- Providing free SMS filtering as a default setting on customers’ devices alongside network-level spam filtering.
- Recommending app-side verified markings as an additional, low-cost safety measure.
Impact
The RCS service in Japan now enables customers to see corporate logos and verification marks directly within the app, giving them immediate visual confirmation that messages come from official, pre-screened accounts. This has become an effective, low-cost countermeasure to SMS phishing, which exploits the ease of sending text messages when only phone numbers are known.
Customer feedback and UI/UX research show that recipients feel far more confident opening and acting on RCS messages than conventional SMS, where only a phone number or alphabets is displayed, and legitimacy is unclear. In parallel, KDDI’s network-level spam filtering (in place since February 2023) and free device-side SMS filtering have reduced reported spam significantly. By combining these filters with app-side verified markings, KDDI and its partners have created a layered approach that strengthens trust, improves security, and enables smooth communication between companies and their customers.
Additional information
Cost:
Low – Only measures for displaying official accounts and verification marks within the app.
Participating Organisations: KDDI
Location:
Asia Pacific
