Kim Jong Un has his own cellular network

The network was built to keep their conversations off the public cellular network and is a result of sanctions that prevent encryption technologies from being exported to the country, said Ahmed El-Noamany, a former senior technical director at North Korean cellular network Koryolink in an interview published on Thursday by the NK News website.

Koryolink is a joint venture between Egypt's Orascom Telecom and Media Technology (OTMT) and the North Korean government. It launched a 3G cellular network in 2009 that has gone on to attract around 2.5 million subscriptions -- about 10 percent of North Korea's population.

"They have another network for the VIPs that is totally separated from everything … a 3G network that is not accessible to normal users," El-Noamany told NK News.

The engineer, who worked in North Korea from 2011 to late 2013, said the network was built this way because sanctions prevented the export of encryption technology to North Korea. To overcome this, the country built a separate network.

"This is a special network which has its own things -- own algorithms, own operating system, own everything," he said.

His comments add somewhat to the mystery surrounding North Korea's complex telecommunications system.

The country runs a two-tier network with most subscribers only able to make and receive calls from domestic numbers. At the second tier, which includes lines at places like foreign embassies, international connectivity is offered but domestic calls are blocked.

The system is part of North Korea's strict controls that attempt to prevent information coming into the country from overseas. Both the fixed-line and cellular networks have the same two-tier structure.

From cellphones, a network search inside Pyongyang reveals two networks, said Kazuteru Tamura, a Japanese journalist who has spent time investigating the system.

One network is accessible from cell phones with local SIM cards and the other from phones with SIM cards sold to tourists and foreign residents. Observers have assumed the two networks were all that were available in the country, and El-Noamany's comments question that assumption.

Recently, a competing cellular operator owned by the North Korean government began competing with Koryolink. It's unknown how or if the new network is related to that private government network mentioned in the interview.

North Korea maintains one of the strictest policies of control on information and people of any country on the planet. Most citizens are unable to travel overseas and even domestic travel is heavily restricted, with permission needed to enter the capital city of Pyongyang. Thousands of North Koreans have risked death to escape the country.