Indonesian engineers may have stolen key fighter jet technologies

A KF-21 Korean fighter jet is coming out of a hangar at the Korea Aerospace Industries (KAI) headquarters in Sacheon, South Gyeongsang, in May 2023. [JOINT PRESS CORPS]

An investigation is in full swing after the recent revelation that Indonesian engineers dispatched to Korea Aerospace Industries (KAI) for joint development of the KF-21 fighter jets allegedly stole related technologies.

The key is whether the leaked data was classified or not.

In particular, Korean authorities must consider the possibility that critical technologies, such as designs, have been leaked.

Multiple sources told the JoongAng Ilbo on Wednesday that a joint investigation team consisting of the state-run Defense Acquisition Program Administration (DAPA), Defense Counterintelligence Command and the National Intelligence Service (NIS) is working at deciphering encrypted and non-encrypted files on the USBs that the Indonesian engineer, whose identity is withheld, took.

One week ago, DAPA said that Indonesian engineers assigned to work on the KF-21 project at KAI, Korea's sole aircraft manufacturer, are under investigation for allegedly stealing fighter jet technologies.

The DAPA initially said the engineers are suspected of trying to save classified data from the KF-21 project on USB devices. At the time, the DAPA said the USB drives mostly contained general documents not tied to strategic technologies that might violate laws on military secrets or defense technology.

Joint investigation team sources said Wednesday that password-protected files take more time to decipher as they require cooperation from the head Indonesian engineer.

He was caught leaving work at a security checkpoint on Jan. 17 with several unauthorized USBs and is currently barred from leaving the country while undergoing questioning.

More than 6,000 files are reportedly saved on the USBs, a greater volume than initially suspected.

"There were some reports that the USB drives contained 49 types of files, but if you look at the number of documents rather than the type, depending on the classification criteria, between 4,000 and 6,600 items were identified," one source said.

If this amount is confirmed, the drives may contain many of the key technologies of the KF-21.

It adds to suspicions that the Indonesian engineer's USB contains "CATIA," a 3-D modeling program for the KF-21. This program provides a three-dimensional version of the fighter jet design and is considered a core KF-21 technology.

"It can be said that the KF-21 CATIA contains the trial and error and know-how that KAI experienced while making the T-50 and FA-50 aircraft," an industry source said. "CATIA is equivalent to KAI's unique intellectual property, and by securing engines, armament and avionics equipment, a prototype of the KF-21 can be made quickly."

Among approximately 15 engineers dispatched from Indonesia, their leader, the individual caught sneaking out the USBs, is said to have joined KAI in 2017.

The investigation team is also investigating the possibility that he may have stolen technical data related to the KF-21 over several years.

The USBs contained multiple reports written in Indonesian, which could be interpreted as circumstantial evidence that the company had an information-sharing system with third parties, including Indonesia, for a long time. The head engineer claimed he had taken them over from his predecessor.

If the USB contains data that has not received an export license (EL) from the U.S. government, it could escalate into a diplomatic issue.

In this case, security liability ultimately lies with KAI, meaning Korea, so when future businesses require U.S. equipment, the United States may demand more stringent conditions or even refuse export approvals.

KAI is facing growing criticism of its alleged complacency and lax security, regardless of whether the data leaked was confidential.

When the leak was first reported in the media on Feb. 2, KAI issued a statement saying "no material that violates the Military Secrets Protection Act or Defense Industry Technology Protection Act has been found" in the USBs, even though the government's joint investigation is still in progress.

"This incident needs to serve as an opportunity to conduct a large-scale security inspection to determine whether important technologies have been designated as military secrets and, if not, why," a military official said.

Responding to the suspicions, a DAPA official said, "This is a matter being investigated by a joint investigation team, and there are limits to what facts can be confirmed at this time."

"We are cooperating with the government authorities' investigation," a KAI official said.

Although Jakarta initially promised to pay 20 percent of the KF-21 project's 8.8 trillion won ($6.5 billion) price tag, the country is currently in arrears by more than 1 trillion won, having only paid around 278.3 billion won thus far.

Seoul plans to begin production of KF-21 fighter jets later this year and deploy 120 KF-21 aircraft by 2032.

Indonesia plans to produce 48 KF-21 jets locally after receiving one prototype and technical data.

BY LEE KEUN-PYUNG, LEE YU-JEONG, SARAH KIM [kim.sarah@joongang.co.kr]