Similar to national identification numbers in other countries, it is used to identify people in various private transactions such as banking and employment.
Many South Korean websites require users to submit a valid resident registration number to create an account.
The RRN has since replaced the number with identification SMS (via phone owners' information), public key certificate (requiring a visit to a bank, since PKC is stored in user's PC or personal device unlike other countries), and i-PIN, Internet Personal Identification Number, which may be obtained via registration of RRN with a governmental site.
[4] Since many South Korean websites require a valid resident registration number (RRN) in order to create an account, this presents many opportunities for identity theft and other types of fraud.
[5] Identity theft and other fraud is difficult to defeat in Korea, because each person's RRN is unchangeable, unlike other nation's identification numbers which can be changed if they are compromised (such as the United States' SSN).
Complaints about identity theft led the South Korean government to implement stiff penalties for using someone else's resident registration number.