SEOUL/LONDON (Reuters) - South Korea has revived a project to build a backup ship navigation system that would be difficult to hack after a recent wave of GPS signal jamming attacks it blamed on North Korea disrupted fishing vessel operations, officials say.
Global Positioning System (GPS) and other electronic navigation aids are vulnerable to signal loss from solar weather effects, radio and satellite interference and deliberate jamming.
South Korea, which says it has faced repeated attempts by the rival North to interfere with satellite signals, will award a 15 billion won ($13 million) contract this month to secure technology required to build an alternative land-based radio system called eLoran, which it hopes will provide reliable alternative position and timing signals for navigation.
"The need for us is especially high, because of the deliberate signal interference by North Korea," a South Korean government official involved in the initiative told Reuters, requesting anonymity as he was not authorized to speak to the media.
The latest jamming campaign from the North began on March 31, lasting nearly a week and affecting signal reception of more than 1,000 aircraft and 700 ships, originating from five locations along the border, South Korean officials said.
Aircraft traffic was not affected because the GPS system is normally used as a backup, not a primary navigation tool, one of the officials involved in telecommunications policy said.
The jamming prompted warnings by South Korea's military to North Korea to stop what it called "provocation" and a protest at the United Nations. North Korea has denied involvement.
South Korea has been on high alert against possible cyber attacks from the North following the North's nuclear and missile tests and threats of war in response to new sanctions imposed by the U.N. Security Council and the South.
The reclusive North and the rich, democratic South are technically still at war since their 1950-53 conflict ended in a truce, rather than a treaty. The North routinely threatens to destroy South Korea and its major ally, the United States.
No major disasters anywhere have been blamed on loss of GPS, although the risks are growing as sea lanes become more crowded.
Part of the problem is that it's not easy to detect a GPS outage caused by jamming.
"When GPS/GNSS (Global Navigation Satellite Systems) fail, transportation is impacted immediately. It slows down, becomes more dangerous, and every mode can carry less capacity," said Dana Goward, president of the non-profit Resilient Navigation & Timing Foundation.
"As short-term backup clocks start to desynchronize with each other ... cell phone towers start to fail, IT networks slow down or fail, financial systems are impacted, management of the electrical grid becomes problematic. That is the really scary part," said Goward.
GPS vulnerability poses security and commercial risks, especially for ships whose crews are not familiar with traditional navigation techniques or using paper charts.
The General Lighthouse Authorities of the UK and Ireland, which tried to pioneer an eLoran system in Europe, conducted simulated communications attacks on ships at sea and said the results "demonstrated the devastating effects of jamming on the ships' electronic bridge systems".
Many vessels, such as fishing boats, lack backup electronic navigation systems.
The United States, Russia and India are all looking into deploying versions of eLoran, which sends a much stronger signal and is harder to jam, as backup.
Installing an eLoran receiver and antenna on a ship would cost thousands of dollars, although cheaper options could include incorporating eLoran systems into satnav devices, according to technical specialists.
Last month, hundreds of South Korean fishing boats returned to port after GPS jamming that also created problems in locating nets at sea, South Korean officials said.
The U.S. Coast Guard said in January that "multiple outbound vessels from a non-U.S. port suddenly lost GPS signal reception", although the vessels were able to navigate using compasses and other aids.
In 2013, the U.S. Navy reported almost certain, intentional jamming of the GPS system of one of its vessels sailing near Iranian territorial waters.
South Korea's eLoran initiative dates to 2011, after a series of incidents also blamed on the North, but was stalled in part by a cancellation of contracts due to a conflict over payment schedules with a U.S. supplier.
Its new plan envisions setting up coastal transmitters by the end of 2019, said Seo Ji-won, a professor at Yonsei University in Seoul, who is on a government advisory panel.
A British-led initiative to create an eLoran system was suspended after failing to keep other European countries interested. A private group called Taviga is in talks with European governments to resume support for eLoran, the company said.
"The situation for this country is different, because there have been real cases of deliberate interference," the South Korean government official said. "We need this."
Editing by Tony Munroe and Nick Macfie