Samsung
Encrypt or Decrypt SD Card auf Samsung
An SD card stores photos, videos, and app files outside your phone's internal storage. Without protection, that data is readable the moment someone removes the card and plugs it into another device or a card reader.
Samsung addresses this with SD card encryption. Once encrypted, the card is bound to your device and your screen lock. Only your phone, unlocked with the same Pattern, PIN, or Password used during encryption, can read the contents. Insert the card elsewhere and it appears empty or unreadable.
Where to find it
Go to Settings ➔ Biometrics and security ➔ Encrypt or decrypt SD card ➔ Encrypt/Decrypt SD card, then confirm with Enter the current Pattern, PIN or Password.
You need an active screen lock before this option works, since the encryption key is derived from it. If you have not set one, add a Pattern, PIN, or Password first, then return to this menu.
Encryption can take a while depending on how much data is stored on the card, and the phone should stay charged during the process. Avoid removing the card until encryption finishes, since interrupting it can corrupt stored files.
Decryption uses the same menu path and reverses the process, making the card readable again in other devices. This is worth doing before selling the phone or moving the card to a different one.