Which technology utilizes barium ferrite for data storage?

Barium ferrite is a type of magnetic material commonly used in various applications that require data storage through magnetic means. This technology is particularly relevant in the context of magnetic stripe cards and similar media where data is stored by the arrangement of magnetic particles, such as those found in Magnetic ID credentials. The magnetic properties of barium ferrite enable it to retain data securely, making it ideal for use in identification cards, access control, and payment cards.

In contrast, smartphones typically utilize flash memory and other electronic components for data storage. Optical scanners rely on light and imaging technology rather than magnetic materials for capturing data. Digital wallets, while they may store information digitally, do not rely on magnetic technology like barium ferrite. Therefore, the association of barium ferrite with Magnetic ID credentials is what makes this option the correct answer.