SK Telecom

SK Telecom is a cellular operator in South Korea, part of the SK Group conglomerate. The company was founded in 1984.

History

2025: $90 million fine for data leakage of 40% of the country's population. Subscribers will be paid compensation

At the end of December 2025, it became known that the largest telecom operator in South Korea, SK Telecom, would pay compensation to subscribers who filed a class action lawsuit against the company in connection with the hacking of its IT systems. During the cyber attack, data was leaked to more than 20 million users, or 40% of the country's population.

The incident in question has become one of the largest in the history of the telecommunications industry in South Korea. The attackers had at their disposal information about 23.2 million SK Telecom subscribers. In total, 25 types of information related to SIM cards were compromised.

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Фото: Reuters

After the cyber-intrusion, the Personal Data Protection Commission (PIPC) formed a joint working group with the Korean Internet Security Agency (KISA), instructing it to investigate the causes of the incident and assess the activities of SK Telecom. The investigation revealed a number of violations. In particular, experts found that the operator did not provide the necessary level of access control and could not detect hacking attempts. It turned out that the SIM card authentication keys were stored in unencrypted text format, and operating systems with known vulnerabilities dating back to 2016 were left without security updates. All this led to the theft of a huge amount of confidential information.

In accordance with the PIPC decision, SK Telecom was fined 134.8 billion won (about $91 million at the exchange rate as of December 22, 2025). In addition, the regulator ordered the company to pay the participants in the class action claim compensation in the amount of 100 thousand won ($67) each. The funds will be provided in the form of cash points and discounts on mobile services. The Korean Consumer Protection Agency Dispute Resolution Commission announced that compensation could be extended to all affected subscribers in the future.^[1]

2023: Recognition of the failure of the launch of 5G networks

In mid-August 2023, SK Telecom, South Korea's largest mobile operator, released a document according to which the commercial launch of 5G networks was far from as successful as industry participants predicted.

The report said 5G technology was over-hyped, but its practical implementation fell short of expectations. Cellular operators presented 5G as a breakthrough platform for the creation of robotic transport, next-generation unmanned aerial vehicles, advanced reality (XR) services and digital twins. But in fact, many such projects have remained unrealized due to the lack of consumer equipment, the immaturity of technologies and services, low or absent market demand, and regulatory problems.

SK Telecom admits 5G network launch was not as successful

SK Telecom emphasizes that some of the tasks set by the international standardization organization ITU-R for 5G have been successfully solved. But other goals as of mid-August 2023 have not been achieved, despite the fact that the first commercial 5G services began to be provided in 2019.

And yet in certain areas, the document notes, 5G technology has provided significant advantages over previous generations of networks. This is a significant increase in throughput with less delay. As a result, a 70 percent reduction in the cost of data transfer per gigabyte was achieved compared to 4G. At the same time, subscribers in 5G networks download 50% more content than those connected to 4G services.

The 6G standard, which will debut approximately in 2030, is expected to avoid mistakes made in the commercial implementation of 5G. SK Telecom said it plans to actively pursue 6G developments and promote South Korea as a global leader in communications technology.^[2]

2019: Launch of the first 5G network

On April 3, 2019, South Korea announced the launch of the world's first commercial fifth generation (5G) network, operating at a nationwide level. For its functioning, telecommunications operator SK Telecom has deployed 34 thousand base stations that cover the most densely populated areas in 85 cities of the country.

The high-speed mobile network, which allows data transfer 20 times faster than the technology, LTE is already operating in some regions, but its official commissioning is scheduled for April 5, 2019 - the launch day of the first smartphone Samsung with 5G support (). Galaxy S10

SK Telecom expects 1 million subscribers to be connected to the 5G network by the end of 2019. In total, the company has 27 million customers by the beginning of April 2019.

As noted by the Reuters news agency, South Korean cellular companies spent billions on marketing campaigns dedicated to the launch of 5G networks. For example, SK Telecom attracted music stars and an Olympic champion to advertise.

Another South Korean operator - KT Corp - is set to offer better tariff plans for 5G users. They will include unlimited internet and the ability to buy 5G devices in installments for four years.

Telecom giants in South Korea planned to launch 5G networks in March 2019, but there was a delay due to the need for additional equipment testing. In addition, SK Telecom was unable to agree with the government on the cost of servicing the new network, which also led to a delay.

SK Telecom reported that the company's base stations are capable of providing subscribers with transmission speeds up to 2.4 Gbps. Such fast Internet access will open up new opportunities not only for ordinary users, but also for companies, significantly accelerating the development of the Internet of Things and self-driving cars.^[3]

Notes