LG Uplus Incorporated Actual Phone Numbers in IMSI... Plans USIM Replacement

Concerns Raised Over Long-Term Exposure of Personal Identification Data
"Enhancing Information Protection by Encrypting IMSI"

It has been revealed that LG Uplus incorporated parts of subscribers' actual phone numbers when designing the International Mobile Subscriber Identity (IMSI), which is used for subscriber identification. In response to concerns about the need to strengthen personal information protection measures, LG Uplus has decided to implement measures such as Universal Subscriber Identity Module (USIM) replacements.

LG Uplus Yongsan Building, Yongsan-gu, Seoul Photo by Yonhap News

According to industry sources on March 17, since the introduction of 4G mobile communications in 2011, LG Uplus has been generating IMSI values using a method that includes part of the subscriber's actual phone number. IMSI refers to a unique 15-digit number assigned to identify subscribers on a mobile network. In contrast, SK Telecom and KT employ methods that utilize random numbers, making predictions difficult. A random number refers to a number assigned arbitrarily without any specific rule.

Although hacking using only the IMSI value is difficult, there are concerns that combining it with other information could lead to additional security threats, such as the creation of cloned phones. There is also criticism that leaving personally identifiable information in a form that could be predicted over a long period was inadequate from a management perspective.

LG Uplus explained that during an internal information security system self-inspection last year, it found that, under the existing provisional system, certain measures such as USIM formatting could be difficult to implement. In addition, upon recognizing this issue, the company held two meetings to discuss countermeasures with the Ministry of Science and ICT, the Korea Internet & Security Agency (KISA), and the National Assembly's Science, ICT, Broadcasting, and Communications Committee.

LG Uplus plans to take measures such as free USIM replacements for customers who wish to participate, starting from April 13. The company has also introduced a randomization system for IMSI values and aims to develop technology by November that will allow IMSI to be changed via software updates without physical replacements.

Lee Sangyeop, Chief Technology Officer (CTO) of LG Uplus, stated, "The existing IMSI system has been operated safely in compliance with international standards," and added, "In 5G Standalone (SA) mode, we plan to further enhance the level of customer information protection by encrypting IMSI."

LG Uplus will soon announce detailed customer guidance and support measures through its website and application channels.

This content was produced with the assistance of AI translation services.