SEOUL - North Korea's Internet went down this week after an apparent attack but most of its citizens will not have noticed the difference in a country that does its level best to seal off foreign influence, experts say.
The mysterious blackout has hit the North since Monday night, after the US warned of a retaliation against Pyongyang's alleged hacking attack on Sony Pictures.
Pyongyang is accused of launching the crippling cyber-attack on Sony for producing "The Interview," a comedy that depicts a fictional plot to assassinate the North's leader Kim Jong-Un.
Through Monday to Wednesday, websites of the North's major state media went dead for hours, while foreign diplomats and journalists in Pyongyang reportedly complained of a temporary shutdown of Internet services.
But such outages that could have crippled businesses and paralysed daily life elsewhere likely went largely unnoticed in the North, where only a trusted few can access the world wide web.
"Most of ordinary people in North Korea have no access to the Internet. Only a handful of elites can use it, with great restrictions," said Kim Seung-Joo, professor at Korea University's Centre for Information Security Technologies (CIST).
"Since North Korea as a whole relies so little on the Internet, the potential damage of the outage will also be quite limited," he said.
The impoverished state ruled by the Kim family tightly controls its 25 million citizens, with all TVs and radios registered with the police and preset to state frequencies.
More than two million use mobile phones but almost all lack Internet connectivity or overseas call features, according to defectors and experts.
The North also has about a million computers - mainly available at educational and state institutions - but most lack any connection to the world wide web.
Instead, a domestic "Kwangmyong" intranet offers e-mail, some online games and access to websites of state bodies and media but little else.
Little for hackers to attack
All online content and e-mail are strictly censored or monitored. And a chat service on the Kwangmyong network was shut recently after its growing popularity among college students unnerved authorities, said Park Kun-Ha, secretary general of the North Korea Intellectuals Solidarity, a Seoul-based news site run by North Korean refugees.
Park estimated the number of intranet users at "some tens of thousands," adding that access to the world wide web remained strictly limited to a handful of top party cadres, propaganda officials and foreign expats.
"North Koreans' lives are not bound by computers or the Internet like the rest of the world," Park said.
Lim Jong-In, another cyber expert at CIST, said hackers may find "little to attack" in one of the world's least-wired nations.
"The North's major national infrastructures are not connected to the Internet, so potential hackers may find little to attack or harm," he said.
North Korea's limited connection to the Internet is based on just four web pipelines that run through China, operated by China Unicom.
It reportedly has only about 1,000 IP addresses registered under its national domain, compared with 112 million in South Korea, but is also believed to run an elite unit of thousands of hackers to wage cyber attacks.
South Korea has accused Pyongyang of launching a series of crippling malware attacks on its government, banks and media websites in recent years, although the North denied involvement.
Lim earlier estimated the North had around 6,000 such hackers, describing it as "one of the world's top five countries" in cyber warfare capability.
Many operate in Chinese border cities such as Dandong under software contractors hired by Pyongyang, he added.
"If the US wants to inflict pain on the North, it would be better to have such software contractors arrested rather than paralysing the North's negligible Internet network," Lim said.