public final class EncryptedFile

Class used to create and read encrypted files. WARNING: The encrypted file should not be backed up with Auto Backup. When restoring the file it is likely the key used to encrypt it will no longer be present. You should exclude all EncryptedFiles from backup using backup rules. Be aware that if you are not explicitly calling setKeysetPrefName() there is also a silently-created default preferences file created at

    ApplicationProvider
         .getApplicationContext()
         .getFilesDir()
         .getParent() + "/shared_prefs/__androidx_security_crypto_encrypted_file_pref__"

This preferences file (or any others created with a custom specified location) also should be excluded from backups. Basic use of the class:

 MasterKey masterKey = new MasterKey.Builder(context)
     .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
     .build();

 File file = new File(context.getFilesDir(), "secret_data");
 EncryptedFile encryptedFile = EncryptedFile.Builder(
     context,
     file,
     masterKey,
     EncryptedFile.FileEncryptionScheme.AES256_GCM_HKDF_4KB
 ).build();

 // write to the encrypted file
 FileOutputStream encryptedOutputStream = encryptedFile.openFileOutput();

 // read the encrypted file
 FileInputStream encryptedInputStream = encryptedFile.openFileInput();

Summary

public @NonNull FileInputStream openFileInput()

public @NonNull FileOutputStream openFileOutput()