ora-19914: unable to encrypt backup

Cause: RMAN could not create an encrypted backup. This message will be accompanied by other messages that give more details about why the encrypted backup could not be created. The most common reason for this message is that you are trying to create a backup that can be transparently decrypted, and the database external security device is not open.
Action: If the external security device is not open, then open it. If the external security device is not configured, then the only type of encrypted backup that you can create is a password-based backup.

no se ha podido cifrar la copia de seguridad
impossible de crypter la sauvegarde
Backup kann nicht verschlüsselt werden
incapaz de codificar a cópia de segurança