Why Did the Prosecutors Need Prosecutor General Han Dong-hoon's Phone SIM Card? ... Prosecutors Say "The SIM Card Is Like a Key"

"Warrant for Seizure and Search of USIM Specifically Specifies Purpose of Use"

Chief Prosecutor Han Dong-hoon (left) and Deputy Chief Prosecutor Jung Jin-woong. [Image source=Yonhap News]

[Asia Economy Reporter Choi Seok-jin] Attention is focused on the mobile phone USIM (Subscriber Identity Module) that the prosecution tried to secure, even leading to an unprecedented ‘physical altercation’ with Prosecutor Han Dong-hoon.

The question arises as to why the ‘media collusion’ investigation team attempted to secure Prosecutor Han’s mobile phone USIM at this particular time.

According to the legal community on the 30th, the ‘media collusion’ investigation team, including Chief Prosecutor Jeong Jin-ung of the Criminal Division 1 at the Seoul Central District Prosecutors’ Office and Prosecutor Jang Tae-hyung, attempted to seize Prosecutor Han’s mobile phone USIM at around 10:30 a.m. the previous day at the Law Training Institute’s Yongin branch office.

As is well known, a physical struggle broke out between Chief Prosecutor Jeong and Prosecutor Han during the process where Prosecutor Han requested the participation of his lawyer and tried to call the lawyer using his mobile phone. After the situation calmed down, they waited about an hour and a half for the lawyer to arrive before proceeding with the analysis of the USIM.

The investigation team analyzed the USIM chip for approximately three hours according to the search and seizure warrant, then returned it to Prosecutor Han and withdrew around 4 p.m.

◆What information is contained in the USIM?= The USIM contains personal information that identifies the subscriber, such as telecommunications provider information and roaming data.

While it is not impossible for a mobile phone user to store contacts or text messages on the USIM through a separate setup process, storage capacity is limited, making it impossible to store photos or voice files.

Moreover, in the case of the iPhone used by Prosecutor Han, unlike Android devices, it is generally accepted that storing contacts or text messages on the USIM is difficult.

Because the USIM does not contain special information, various speculations have arisen about the prosecution’s background for seizing Prosecutor Han’s USIM, including that it was a ‘showy search and seizure’ or an attempt to seize the moment when Prosecutor Han would unlock his phone.

◆Prosecution: “The USIM is like a key”= The prosecution’s position is that this USIM seizure was carried out as an extension of the digital evidence analysis (forensics) of Prosecutor Han’s mobile phone.

In particular, the reason they tried to secure the USIM again, which had been returned during the previous mobile phone seizure, was because Prosecutor Han did not cooperate with the mobile phone forensic work.

A prosecution official stated, “The search and seizure warrant for the mobile phone USIM is different from that for a computer hard disk or the mobile phone itself, and it is not done by imaging the entire device as a whole. There is no warrant that allows imaging the entire USIM to view all information.”

The official added, “The warrant for the USIM seizure does not simply state ‘seize this USIM,’ but specifies the analysis methods, such as what information will be searched, how the execution will be carried out, and what materials can ultimately be seized, with concrete limitations.”

This can be seen as a rebuttal to criticisms that the forensic analysis of Prosecutor Han’s mobile phone USIM being completed in three hours was a fruitless search and seizure.

The official also emphasized, “The mobile phone USIM can be likened to a house key. Just as it would be difficult to recognize evidence if you obtained the key and searched the entire house, even if you have a warrant to seize the USIM, the accessible information is specifically limited.”

In other words, the warrant is issued very specifically not just to examine the USIM itself but to access other information using the USIM.

Some industry insiders say that the authentication information contained in the USIM could be used to access KakaoTalk or Telegram servers.

The official explained the background of this seizure, saying, “In most cases, when a search and seizure warrant is issued for a mobile phone, suspects cooperate with the investigation team’s forensic work. However, Prosecutor Han did not cooperate with the forensics and thus the process could not start, which is why they proceeded to secure the USIM.”

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