Complex sentence: The 10000 won note has 21 security features, 5000 won note with 17, and 1000 won note with 19 security features.But only 13 of them are available to the public, other are confidential.
Split into simpler sentences: The 10000 won note has 21 security features, 5000 won note 17, and 1000 won note 19. The details of only 13 are available to the public, other are confidential.