Question: The winner of 2003 East Asian Football Championship is controlled by what association?

Context paragraphs:
EAFF E-1 Football Championship: EAFF E-1 Football Championship, known as the East Asian Football Championship from 2003 to 2010, and the EAFF East Asian Cup for the 2013 and 2015 editions, is a men's international football competition in East Asia for member nations of the East Asian Football Federation (EAFF).  Before the EAFF was founded in 2002, the Dynasty Cup was held between the East Asian top four teams, and was regarded as the unofficial East Asian Championship.  There is a separate competition for both men (first held in 2003) and women (first held in 2005).  There was also a combined points competition in 2005, where the results of the men's and women's teams are added together (not including qualifiers).

2003 South Korea national football team season: In 2003 the Korea Republic national football team had 15 matches played.  6 of these were qualification matches for the 2004 AFC Asian Cup, 3 were final matches of the 2003 East Asian Football Championship and the rest were friendlies.

2003 East Asian Football Championship Final squads: 2003 East Asian Football Championship Final squads

Guam national under-20 football team: The Guam national under-20 football team is the national association football youth team for the United States territory of Guam and is controlled by the Guam Football Association.  They are affiliated with the Asian Football Confederation's East Asian Football Federation region.

Guam national football team: The Guam national football team is the national association football team for the United States territory of Guam and is controlled by the Guam Football Association.  They are affiliated with the Asian Football Confederation's East Asian Football Federation region.

SAFF Championship: The SAFF Championship, also called South Asian Football Federation Cup (previously South Asian Football Federation Gold Cup), is the main association football competition of the men's national football teams governed by the South Asian Football Federation.  Previous names have included the South Asian Association of Regional Co-operation Gold Cup in 1993 and South Asian Gold Cup 95 in 1995.  Eight teams compete in the South Asian Football Federation Tournament.

2005 East Asian Football Championship: The 2005 EAFF East Asian Football Championship is a football competition between teams from East Asian countries and territories held from 31 July 2005 to 7 August 2005 in the land of South Korea, with the qualifiers held in Taiwan during March 2005.

2003 East Asian Football Championship: The 2003 EAFF East Asian Football Championship is a football competition for East Asian countries and territories.  The qualifiers were held in February and March 2003 in Hong Kong and the final was held in December 2003 in Japan.  South Korea was the winner with Japan as runner-up.

Northern Mariana Islands national football team: The Northern Mariana Islands national football team represents the Commonwealth of the Northern Mariana Islands in international men's football.  The team is controlled by the governing body for football in the Northern Mariana Islands, the Northern Mariana Islands Football Association, which is a member of the East Asian Football Federation (EAFF) and an associate member of the Asian Football Confederation (AFC).  The federation is not a member of the world governing body FIFA and so whilst the national team is eligible to enter AFC and EAFF-run competitions, they are currently ineligible for global competitions such as the FIFA World Cup and FIFA Confederations Cup.  As such, they do not have an official FIFA ranking.  However, the team have been consistently ranked as one of the worst teams in the world on the Elo ratings and are in fact, at July 2016 rated as the worst men's senior international team in the world in a ratings system that also includes a number of other non-FIFA teams.  Following the completion of the preliminary qualifying round for the 2017 EAFF East Asian Cup the team have won only one official competitive match against international opposition and have a goal difference of −78 in official matches.  The team have never qualified for the finals of a major tournament and beyond friendlies and qualifying matches, their only official competition has been in an exhibition tournament in the regional Micronesian Games in 1998, which they won, to date their only tournament success.

South Korea national football team: The Korea Republic national football team represents South Korea in international association football and is controlled by the Korea Football Association.

Supporting paragraphs: 2003 East Asian Football Championship South Korea national football team
Answer: Korea Football Association