Updated December. 24, 2011 20:34
The South Korean military has obtained intelligence that top brass in North Korea are changing communication frequencies and encrypting system to avoid wiretapping.
The move comes after South Korean media reported that Kim Jong Un, the successor to the late leader Kim Jong Il, gave his first order to his military just before the Dec. 19 announcement of his father`s death.
A military source said Friday that the South Korean military has had trouble collecting special intelligence obtained by wiretapping North Korean telecommunications since South Korean media reported that Kim Jong Un ordered North Korean troops to stop military exercises and immediately return to base.
"No additional special intelligence has been secured from the telecommunication system used to deliver Kim Jong Un`s first order to his entire military," the source added. "It appears that the North Korean military is changing the frequency bandwidth or encryption system out of fear that the South Korean military is wiretapping."
The North issues all instructions, including orders from the leadership, to its units through encrypted or coded words to maintain communication security. Reportedly, Kim Jong Un`s first order was quickly delivered to all military units in encrypted form Monday morning just before state-run media announced Kim Jong Il`s death.
After South Korean media reports said Seoul decrypted the detailed contents of the communication, Pyongyang`s military has begun to act to prevent the South from collecting further intelligence, military intelligence in Seoul said.
Another source said, "There`s the possibility that the North is delivering follow-up instructions only through its optical cable networks, which cannot be wiretapped by the South Korean military, after changing its communication frequencies or encryption system."
Rep. Kim Se-yeon, a member of the South Korean ruling Grand National Party, claimed at a parliamentary session Friday that optical fiber cables provided by the South were buried under ground, blocking wiretapping efforts.
Since the Kim Dae-jung administration, Seoul has been providing the North with telecommunication equipment including optical cables to help the impoverished communist country improve its communication networks. The South Korean military said communication using optical cables is harder to detect than those using wireless networks.