How should I submit a copy of my passport and alien registration card when applying for a job?

I am currently looking for a new job, and I heard that I need to submit my passport and Alien Registration Card (ARC) to apply. However, I am hesitant to submit my passport number or ARC number, which contain important personal information, without the job being confirmed yet. In this case, should I submit sensitive information with blind processing, or should I send it as it is? If anyone has advice from a similar experience in Itaewon in the past or has received such requests while job hunting in the Gangnam area, please share. With so much information being exchanged these days, I am unsure how to handle concerns about personal information protection.