North Korea’s Internet access, minimal as it is, was restored by Tuesday after being knocked out for most of Monday. The outage has been reported as a possible retaliation by the United States for Pyongyang’s alleged role in the hacking of Sony Pictures Entertainment earlier this fall.

There are also claims that China, becoming more tired of North Korea’s aggression, could have caused the outage. However, Beijing’s Foreign Ministry rejected this idea, with a spokeswoman stating that the accusations had “no basis in reality” and were “extremely irresponsible, unprofessional, and misleading,” according to the BBC.

North Korea has basic Internet access that is limited to a small part of the population. To own a personal computer, individuals must get permission from the authorities and register with the police, as noted by Vox. Depending on their job, people either use Kwangmyong, an official intranet with restricted features, or the actual Internet that the rest of the world uses. The latter is accessible only to a very small group of government officials.

“North Korea’s circle of internet users is so small that the country has only 1,024 IP addresses for 25 million people, whereas the US has billions of IP addresses for 316 million people,” writes Vox’s Max Fisher.

New Hampshire-based Dyn Research, an Internet performance analysis firm, said in a posting on its web site that North Korea’s experience over the past few days, which include “a long pattern of up-and-down connectivity, followed by a total outage, seems consistent with a fragile network under external attack,” but that it also could have been due to something more common like a power outage.

Dyn’s Doug Madory told the New York Times that North Korea’s “networks are under duress” in what seemed “consistent with a [distributed denial of service] attack on their routers. That kind of attack involves overloading servers with traffic until they break down.

But while the country was largely back online Tuesday, there were still some lingering stability issues with its Internet connection.

The U.S. government has not acknowledged a role in the outage, but it came just days after President Obama warned that a “proportional” response was coming “in a place and a time and a manner that we choose.”

On Monday, State Department spokeswoman Marie Harf told reporters that “a range of options” is being considered by the government, but would not confirm whether it had been behind North Korea’s Internet problems.

[photo credit: zennie62]