YP Kim delivered expert crypto-linguistic service in Japanese and Korean during World War II, the Korean War, and through the USS Pueblo crisis of 1968. He was the face of US Korean language cryptanalysis for over 20 years.
 
During World War II, Kim was a senior figure in the army’s foreign language program and a Japanese language cryptanalyst. As the war was ending, he moved on to censorship work in San Francisco and in post-war Japan. Then, in South Korea, he performed Korean language translation, taught Korean, and wrote a Korean language instruction book.
 
When the Korean War broke out, Kim provided desperately needed Korean language support, directly contributing to notable successes, including the risky amphibious landing at Inchon. His translations of North Korean reactions allowed US forces to press their advantage and helped save the trapped US 7th Army. He interrogated POWs, advised Low Level Voice Intercept tactical personnel, surveyed an island location for direction-finding purposes, and even worked on Chinese cryptosystems. Kim served as the lead interpreter for the United States during negotiations to end the war—including reviewing the final truce document in 1953.
 
Kim continued to work for the Army Security Agency after the war. For many years he was the “first call” whenever Korean interpreters were needed.
 
Kim was an NSA civilian when the North Koreans seized the USS Pueblo in 1968. He personally reviewed the transcripts for NSA, providing the linguistic evidence to the United Nations that the Pueblo had not violated North Korean territorial waters. He served as advisor for the US ambassador to the UN. He concluded his career at NSA as a senior language advisor for the Korean problem.