Cryptographic erase is a method of making encrypted data inaccessible by deleting the encryption keys needed to decrypt it. Rather than overwriting every storage location, the device removes or invalidates those keys, leaving the remaining data unreadable when the encryption is properly implemented.
It matters when retiring, resetting, or repurposing devices that may contain sensitive information. A full erase designed to remove encryption keys is different from deleting files or turning on Airplane Mode, which does not erase local data or prevent physical access. In practice, cryptographic erase depends on the device having encrypted the data and securely managing its keys; it should not be assumed that every reset performs one. For secrets such as cryptocurrency recovery phrases, avoid storing them on general-purpose devices and follow the manufacturer’s secure erase procedure.