Tiffany Hwang performs music.
Stephanie Young Hwang ( born August 1 , 1989 ) , known professionally as Tiffany or Tiffany Hwang , is an American singer based in South Korea . After four years of training , Tiffany debuted as a member of girl group Girls ' Generation ( and later its subgroup TTS ) in August 2007 , who went on to be one of the best-selling artists in South Korea and one of South Korea 's most popular girl groups worldwide .