By Yan Zhuang and Elian Peltier

MELBOURNE— The cellphones, procured on the black market, performed a single function hidden behind a calculator app: sending encrypted messages and photos.

For years, organized crime figures around the globe relied on the devices to orchestrate international drug shipments, coordinate the trafficking of arms and explosives, and discuss contract killings, law enforcement officials said. Users trusted the devices’ security so much that they often laid out their plans not in code, but in plain language.

Unbeknown to them, the entire network was run by the FBI, in coordination with Australian police.

On Tuesday (8), global law enforcement officials revealed the three-year operation, in which they said they had intercepted over 20 million messages and arrested at least 800 people in more than a dozen countries.

The operation, known as ‘Trojan Shield’, represents a breakthrough for law enforcement. Although the authorities have cracked or shut down encrypted platforms in the past — such as one called EncroChat that the police in Europe successfully hacked — this is the first known instance in which officials have controlled an entire encrypted network from its inception.

Europol, the European police agency, described the effort as “one of the largest and most sophisticated law enforcement operations to date in the fight against encrypted criminal activities.”

“Countless spinoff operations will be carried out in the weeks to come,” Europol said in a statement. American law enforcement officials were expected to announce further arrests Tuesday.

In Australia, the effort ensnared domestic and international organized crime groups and outlaw motorcycle gangs, with more than 200 people arrested, officials said. In Sweden, police arrested 155 people on suspicion of serious crimes and prevented the killing of 10 people thanks to the operation, authorities said in a statement. The operation also targeted Italian organized crime and international drug trafficking organizations, and hundreds more people were arrested in Europe.

“We have been in the back pockets of organized crime,” Reece Kershaw, the commissioner of the Australian Federal Police, said on Tuesday.

The FBI’s operation, according to court documents that the Justice Department unsealed Monday (7), had its origins in early 2018 after the bureau dismantled a Canadian-based encryption service called Phantom Secure. That company, officials said, supplied encrypted cellphones to drug cartels and other criminal groups.

Seeing a void in the underground market, the FBI recruited a former Phantom Secure distributor who had been developing a new encrypted communications system called Anom. The informant agreed to work for the FBI and let the bureau control the network for the possibility of a reduced prison sentence, according to the court documents. The FBI paid the informant $120,000, the documents said.

Anom devices were cellphones that had been stripped of all normal functions. Their only working app was disguised as the calculator function: After entering a code, users could send messages and photos with end-to-end encryption. Over three years, more than 12,000 Anom devices were sold to over 300 criminal syndicates operating in more than 100 countries, according to Europol.

Working with the Australian authorities, the FBI and the informant developed a “master key” that allowed them to reroute the messages to a third country and decrypt them, ultimately intercepting more than 27 million messages.

The authorities also relied on the informant to get the devices into the highly insular criminal networks. The informant started in October 2018 by offering the devices to three other distributors with connections to organized crime in Australia.

A big break, law enforcement officials said, came when they were able to get one of the devices into the hands of Hakan Ayik, an Australian who fled the country a decade ago and whom the police believe has been directing drug imports from Turkey.

Jean-Philippe Lecouffe, deputy executive director of Europol, said the operation gave law enforcement “exceptional insight into the criminal landscape.”

Through the encrypted cellphones, criminals organized the shipment of cocaine from Ecuador to Belgium in a container concealed within cans of tuna, according to U.S. court documents. Cocaine was also trafficked in French diplomatic sealed envelopes out of Bogotá, Colombia’s capital.

Australian authorities acknowledged that Anom had carried only a small percentage of the total volume of encrypted communications sent by criminal networks. But they said that Anom had an advantage: Those running it were able to listen — directly — to the target audience and give users what they wanted.

After users spoke of desiring smaller, newer phones, authorities began to provide them.

Australian officials said they had revealed the operation Tuesday because of the need to disrupt dangerous plots currently in motion and because of limited time frames for legal authorities invoked to intercept the communications.

The Anom website previously displayed sleek graphics and glossy videos reminiscent of Apple ads. On Tuesday, it bore a new message: Users who wanted to “discuss how your account has been linked to an ongoing investigation” could enter their account details.

Europol said that in addition to the 800 arrests, operations conducted in the past days in 16 countries had led to 700 house searches, the seizures of tons of drugs, 250 firearms, 55 luxury vehicles and $48 million in several currencies and cryptocurrencies.

-New York Times