SEOUL—Samsung Electronics Co. is releasing a variant of its newest flagship phone meant to boost adoption of blockchain, according to people familiar with the matter—a tall task for a next-era technology that still puzzles many consumers.

The world’s largest smartphone maker will offer a Galaxy Note 10 marketed as a “KlaytnPhone,” named after a South Korean blockchain platform, the people said. It will be sold starting Thursday, they say, only in South Korea.