By Sunny Um Wired Korea 
  
The use of an instant messaging app for gruesome sex crime should be beyond the expectations of ordinary people, who usually go to a messenger app to say hello to friends or make appointments with them for lunch. But a sex-crime scandal revolving around an encrypted messenger app, Telegram, is rattling the Korean society. 

The suspects of organized crime lured women, some of them underage, with fake job ads to send their photos and personal information. They allegedly used them to blackmail the respondents to shoot porn photos and videos, and shared them with tens of thousands of members of the “nth rooms,” or the paid chatrooms on Telegram. 

It is not just the pornographic materials but the acts the victims were forced into that are abhorring. A case in point involved a victim who was blackmailed to carve her name into her skin. The culprits were nothing short of demonic when they forced the victims into this and other horrendous acts. 

Cho Joo-bin, one of the main suspects, himself said to reporters on March 25, “Thank you for ending my unstoppable life as a devil.” He made the remarks when he was taken from the Jongno Police Station to the prosecutor’s office for further investigation. 

No less shocking than the crime itself is the sheer number of people that paid to view and download the materials and share them with others. At the peak, an estimated 260,000 Telegram IDs reportedly accessed the chatrooms, but the police believe the number of actual users hovers around 6,000, given that many of them were assumed to use multiple IDs. 

At the moment of writing, more than 2.6 million people signed a public petition to the government to disclose Cho's personal information. Another petition, endorsed by over 1.9 million people, demanded the identity of every member of the nth chatrooms. 

Cho may be an administrator, but he is not the one who opened the nth rooms. The creator is believed to be a man called “GodGod,” who is wanted by the police. He went into hiding last March, saying that he could not go on with the crime because he felt “sorry to the victims.” 

Experts say it will be extremely difficult to identify and arrest GodGod and other suspects, given that messages are encrypted on Telegram for anonymity. As the operation was done on Telegram, an instant messaging app that offers secured anonymity.  

Telegram, developed by Russian brothers Nikolai and Pavel Durov, is appealing to those who give priority to data protection and freedom of speech. It is also appealing to those looking for a “safe haven” for digital crimes like those committed in the nth rooms on Telegram.  

“In principle, Telegram is not much different from any other messaging apps. But the chat data on this app is encrypted, so no one can tap into it,” says Lee Sang-jin, a professor at the graduate school of information security of Korea University. 

A regular chat on Telegram is given client-side encryption, with logs, images, videos and files encrypted on the client’s device before being sent to Telegram’s cloud server. When the encrypted data is stored in the cloud server, the encryption keys are kept at unidentified locations. 

“This way local engineers or physical intruders cannot get access to user data,” Telegram writes on its website. 
 
A secret chat on Telegram is made even more secure with the use of end-to-end encryption. Only the sender and recipient are allowed to read the data with a key to which even the service provider is not given access. 

Still better, the data, including the chat log, is not saved on the server. It does not leave any tracks regarding who sent what message at what time. No matter how many servers the data goes through, only the end recipient is able to decrypt and read the message from the sender. 

It was this secret chat that Cho and other suspects used to share pornographic content. Cho allegedly charged up to $1,600 in cryptocurrency for private chatroom membership. 

That is not all. Telegram users can hide their personal information, such as mobile phone numbers and real name, and use a “User ID” instead. They also can withhold their personal information from the people they have added in the list of friends. Police cannot collect personal contacts of those people who use User IDs. 

Investigation is made all the more difficult because Telegram’s offshore server cannot be accessed by the Korean law enforcement agencies. Professor Lee of Korea University says, “For instance, police can comb the office of Kakao Talk, a Korea-based messenger app, (with a search warrant from the court). But Telegram’s server is not located in the nation,” 

In general, Telegram refuses to respond to queries by law enforcement agencies. Telegram reportedly declined to give chat details of the terrorist group ISIS module Ansar-ul-Khilafa Kerala when it was requested by the National Investigation Agency of India in June. 

Finding the operators of the nth rooms and their members and bringing them to justice may not be impossible, says Kim Seung-joo, another professor at the graduate school of information security of Korea University. He says their vulnerability lies in the mediation of cryptocurrency exchanges in the trade of digital pornography. 

“Tracking down the users of the nth rooms is hard, but it will not be impossible when assistance is provided by relevant cryptocurrency exchanges,” Kim says. 

Sex crime, however, will not end with the nth rooms on Telegram. Experts say there are already signs their members are moving to other encrypted messenger apps such as Signal. 

“Criminals always try to find a messenger that ensures that user information is not traceable. As the problem of Telegram has risen above the surface and the police have already widened their investigation, some criminals would now try to find a messaging service that seems more lucrative,” Lee says.