This is the 3818th most frequent Korean word.
신원
Identity.
In this sentence, '신원' refers to someone's identity, such as their name and background.
그의 신원이 밝혀지지 않았습니다.
His identity has not been revealed.
Here, '신원' indicates the concept of identity to be verified, such as ensuring that someone is who they claim to be.
신원 확인이 필요합니다.
Verification of identity is needed.
In this context, '신원' pertains to the idea of a person's confidential information or personal identity.