Google Korea plans to introduce an age-verification system to its search engine later this year that will restrict adult-themed searches to those 19 years of age and older, it said Thursday.

Users will be asked to verify their age when searching for any of about 700 words in Korean judged to be adult and supplied to the portal by the Korean government, said Lois Kim, a spokeswoman for the company in Seoul.

Users will have to enter their name and national resident registration number, which will be checked against a database to verify the user -- or at least the person whose data has been entered -- is old enough.

The system will be combined with a localized version of the SafeSearch system that is already used on Google's main English-language search engine to ascertain the context of the search so that queries for, for example, "rape" are challenged but those for "rape shelter" are not.

The company hopes to enable the system starting Sept. 1. Similar systems are in use by all of Korea's major Internet search portals.

The Internet has penetrated life in Korea perhaps more than it has in many other countries and brought citizens numerous benefits but also problems. In response, the Korean government has discussed regulating certain aspects of online life and has even blocked access to some Web sites, such as those related to North Korea.

In 2004, access was restricted to Web sites hosting a video of a Korean hostage being beheaded in Iraq.

Google is becoming more active in South Korea and recently began hiring people to work at a new research and development center planned for Seoul. It faces stiff competition in the Korean market from established local search engines including Naver, Empas, and Daum.