Sungnam, South Korea - The black-and-white photographs that were published last month in a North Korean newspaper appear no different from other propaganda coming from North Korea: they show the supreme leader, Kim Jong-il, touring a steel plant in a fur cap and his trademark sunglasses.
It is the pudgy but stern-faced young man next to him, dressed in a snappy Western suit and dutifully scribbling in a notebook, who has spurred intense speculation. Could this unidentified man be just a plant manager? Or could this be the first public appearance of Kim Jong-un, the North Korean leader's third son and heir apparent?
"There, see how his face is in focus and illuminated even more than Kim Jong-il himself?" said Cheong Seong-chang, a specialist on North Korean politics at the Sejong Institute. "There is a high possibility that this is Kim Jong-un."
Little is known about the inner workings of the secretive North Korean government, not even the identity of the heir apparent. But if Mr. Cheong is right, the enigmatic photographs are the latest signs of the desperate push that the North Korean government is making to build a cult of personality around the son, who is believed to be 27, to prepare him to assume control as the current leader's health declines.
The elder Mr. Kim, 68, appeared to suffer a stroke two years ago, and there have been recent reports that he is suffering from kidney disease.
Analysts say that if Mr. Kim dies too soon, his son could be pushed aside in a scramble for power among political and military elites that would end the family's dynastic rule and might even bring about the collapse of the impoverished totalitarian state.
While this internal struggle is going on, problems continue to mount. A ham-handed currency revaluation last fall, aimed at reasserting central control over the economy, is reported to have badly backfired, producing unrest and disaffection with the government.
At the same time, the spread of cellphones and DVD players has broken the North's self-imposed isolation, giving many of its citizens a sense for the first time of how poor and backward their country has become.
Recently, the government is said to have given mass promotions and luxury cars to officers in the nation's powerful military, in a bid to cement their loyalty. Indeed, the sinking last month of a South Korean warship, which many South Koreans now suspect was the work of a North Korean torpedo, is widely seen in the South as a show of strength by the North aimed at winning the military's support for the younger Mr. Kim.
Despite the breakdown of communications barriers, reliable information on the political system remains scant. Photographs like those that appeared in last month's Rodong Sinmun, the ruling party's newspaper, are among the limited evidence that analysts and intelligence experts must rely on as they try to understand the efforts to shore up the Kim dynasty for a third generation.
"This remains Kremlinology," said Lee Ki-dong, a researcher on North Korea at the Institute for National Strategy, referring to the cold-war-era study of politics in the former Soviet Union. "We have to scrutinize the Rodong Sinmun as if we were looking for nuggets in a gold mine."
Not much is known about the man who could become the next leader of the unpredictable, nuclear-armed country, even including what he looks like. The only firsthand account comes from a Japanese chef who once worked for the Kim family and knew Kim Jong-un only as a personable and precocious boy. The only known photograph of him was taken when he was 11 years old.
It is also unknown whether Kim Jong-un has any rivals. For a time, North Korea watchers regarded the leader's eldest son, Kim Jong-nam, 39, as the most likely heir - until he was caught by Japanese authorities using a fake passport to visit Tokyo Disneyland. He now lives in Macao, giving occasional paid interviews to Japanese television.
Reports out of North Korea indicate that the government is trying to build a cult of personality around Kim Jong-un, just as it did during the last succession, when the current leader replaced his father, the North's founder, Kim Il-sung. But while Kim Jong-il is believed to have had two decades as heir before assuming power after his father's death in 1994, his son is being rolled out much faster.
Moreover, some experts say, the average North Korean is growing worldly and aware of life outside the country's borders, making it increasingly unlikely that the government's often bizarre propaganda efforts will succeed.
On Monday, the Daily NK, a Web site that specializes in information on North Korea, said it had obtained an internal propaganda document that called Kim Jong-un the Youth Captain and quoted his father (who has his own title, Dear Leader) praising his loyalty and good works. The documents also extolled the son for such achievements as managing a fireworks display last year in Pyongyang, the capital, and becoming a proficient driver of military vehicles, the Daily NK reported.
"He is a genius of geniuses," the document says. "He has been endowed by nature with special abilities. There is nobody on the planet who can defeat him in terms of faith, will and courage."
Mr. Cheong, the analyst, said that members of local North Korean work units and government employees had been taught a new song titled "Footsteps," which lauds Kim Jong-un's fitness to follow his father as leader.
Kim Jong-il has been rushing to prepare the ground for his son in other ways, analysts say. They said that wiretaps of North Korean phones by the South's intelligence agency revealed that the younger Mr. Kim was appointed to a top post in the ruling party's internal security apparatus last year and that he now worked in the same building as his father.
The analysts have offered many predictions about what may happen when the current leader does die. One is that his brother-in-law, Jang Song-taek, 64, widely seen as the second most powerful member of the inner circle, could serve as a regent until the younger Mr. Kim is ready to rule - or simply hold onto power for himself.
"The signs are that the elite do not take Kim Jong-un seriously," said Kim Yeon-su, a professor of North Korean studies at the National Defense University in Seoul. "This is the final stage of the Kim family dictatorship."
Su-Hyun Lee contributed reporting from Seoul, South Korea.