Gets or sets a value indicating whether metadata streams are encrypted. The default is true; with
false, a metadata stream stays readable to tools that index files without the password.
public bool EncryptMetadata { get; set; }
ISO 32000-2 §7.6.4.2, Table 21 (EncryptMetadata), §7.6.4.3.2 step f and §7.6.4.4.9 (Algorithm 10). Meaningful for
V 4 and later, so Rc4 (V 2) always encrypts metadata and a save that combines
it with false is refused. Unencrypted metadata streams are also left uncompressed.