January 26, 2026
SEOUL – Osan Air Base, a key hub for South Korea-US air operations, has become the center of controversy over how sensitive personal data of Korean nationals is handled — raising concerns about consent, oversight and control over when such information is collected and retained by a foreign military authority.
According to multiple sources on Sunday, the South Korean Air Force’s Operations Command headquartered at Osan Air Base in Pyeongtaek, Gyeonggi Province, is collecting full resident registration numbers of reservists mobilized for training and submitting them to the US 7th Air Force, which operates the base jointly with South Korean forces.
“In the past, reservists could enter the base under Korean military escort,” a South Korean Air Force official told The Korea Herald, speaking on condition of anonymity. “But since US forces now manage access control, identity verification standards have changed.”
“Previously, the Military Manpower Administration provided only basic information such as name, contact details, and date of birth,” the official added. “Now, US forces are requesting full resident registration numbers.”
The resident registration number is a 13-digit code that serves as South Korea’s primary national ID, similar in function to the US Social Security number. It encodes an individual’s date of birth, gender and place of registration. When combined with a person’s name, it can be used to open bank accounts or obtain mobile phone services, making it highly sensitive.
Under the revised process, the Air Force requests this personal data from the Military Manpower Administration — the agency responsible for managing conscription and reserve forces — about a month before training. The information is then submitted to US forces, who issue base access passes.
Internal documents outlining the procedural changes have already been circulated, another military official said. Approximately six reserve training sessions are held at the base annually, with about 50 reservists participating in each.
The controversy centers on where the collected personal data ultimately ends up, how the information is provided, and consent.
Information submitted for base access is stored in the Defense Biometric Identification System (DBIDS), a US Department of Defense-managed identity and access control system used across US military installations worldwide. US Forces Korea regulations — specifically USFK Instruction 5200.08 — stipulate that the identities of all external visitors are to be registered in the system.
Once DBIDS records the identities of visitors, the data remains in the system even after access to a base ends, making it difficult for ordinary Korean citizens to determine how long their information is retained, how it is used or whether it can be withdrawn.
The 51st Fighter Wing under the US Seventh Air Force, which oversees US facilities at Osan, said the system is intended to enhance gate operations, noting that once information is registered, future access procedures can be “streamlined.”
US Forces Korea also said the data is used solely for “identity verification purposes,” adding that further details could not be disclosed.
Another potential issue is the legality of collecting and handing over the information.
Under Korean law, individuals have the right to be informed about how their personal data is collected, used and managed. They are also entitled to give consent and to define the scope of that consent, as well as to request the correction or deletion of their data.
The law further requires data handlers to collect only the minimum amount of personal information necessary, and to do so in an appropriate manner.
South Korea’s Air Force, meanwhile, has not clarified whether it can lawfully collect and provide sensitive personal data to a foreign military authority without the consent of the individuals concerned.
The Military Manpower Administration also deferred the issue to the Defense Ministry, which said it “sets general policy while operational details are handled by each service.”
Hwang Suk-jin, a professor at Dongguk University’s Graduate School of International Information Security, said the military should consider alternative identification methods.
“Resident registration numbers are classified as highly sensitive personal information. Given that such numbers are extremely difficult to change, it would be more prudent to explore alternative identification methods, such as passport numbers, which can be renewed,” Hwang said.
“With the aftereffects of major data breaches last year at major companies such as Coupang, Lotte Card and KT still lingering, it is worth questioning whether providing resident registration numbers to foreign military authorities without individual consent is appropriate,” he added.
Despite such potential problems, the reservists who would be subject to the new rules will have little choice if the measures are enforced.
Unlike civilian contractors and other voluntary visitors, such as those entering the base for paid work or official events, reservists are mobilized by law rather than by choice and have little room to refuse or negotiate how their personal information is shared.
Those who completed active service in units stationed at Osan, including the Air and Missile Defense Command, the Air Defense Control Command and the Air Force Operations Command, are typically assigned there for reserve training.
Also, reservists may be mobilized to Osan Air Base depending on their former unit, specialty or operational requirements. This includes personnel deemed essential to combined South Korea-US military operations — such as translation, transportation and air operations — even if they are based outside the Osan area.
Changing training locations is difficult. The Military Manpower Administration does not allow transfers based on personal preference, and relevant laws permit changes only under limited circumstances, such as relocation of residence.
Training postponements are limited to unavoidable reasons such as illness, accidents, national examinations or disasters. As a result, concerns over personal data handling alone are unlikely to exempt reservists from attending training.
Similar arrangements exist at other joint facilities, though with notable differences.
Gunsan Air Base, another South Korea-US joint installation in North Jeolla Province, also conducts reserve training on base. However, entry procedures there have reportedly been less stringent.
At Camp Humphreys — the largest overseas US military installation in Asia — reserve training has been conducted since 2023 for former Korean Augmentation to the US Army soldiers, or KATUSA, whose personal data had already been registered during their service with US units.
The next reserve training session at Osan Air Base is scheduled for mid-April. “The enhanced security measures will not affect training schedules or formats,” South Korea’s Air Force and Air Force Operations Command said.
The changes are widely seen as part of a broader restructuring of base access following a special counsel’s raid last year.
Osan Air Base has three entry gates. Until last year, one gate located near South Korean facilities was managed by Korean forces in practice, allowing entry with Korean government or military identification even without US-issued access passes. Reservists attending training at the base also used this gate.
That arrangement changed after a special counsel team investigating insurrection-related allegations linked to former President Yoon Suk Yeol’s Dec. 3, 2024, martial law declaration conducted a raid at Osan Air Base in July last year.
The raid was part of an investigation into allegations that the Yoon administration conducted drone operations over North Korea, which investigators say may have been intended to justify his martial law scheme. The special counsel team reportedly entered the base through the Korean-controlled gate.
In response, US forces announced plans to directly control all gates and reorganize access procedures, effectively reclaiming authority over gate control from South Korean forces.
To some, such a move may appear unilateral.
However, under the South Korea-US Status of Forces Agreement, Osan Air Base is classified as a facility provided by South Korea to the United States, granting US forces authority over the base’s operation, security and management.
In October, Lt. Gen. David Iverson, commander of the US Seventh Air Force — who also serves as deputy commander of US Forces Korea and the US co-chair of the SOFA Joint Committee — sent a letter of protest to South Korea’s Foreign Ministry regarding the raid. According to local reports, the letter went unanswered.
US forces have since described the changes as “enhanced security procedures.”
New entry rules initially slated for January are now expected to take effect from mid-February after a grace period. Korean and US personnel are currently jointly stationed at the affected gate.