How the standard security handler encrypts a saved document's strings and streams.
public enum PdfEncryptionAlgorithm
ISO 32000-2 §7.6.2 (Table 20, V), §7.6.3 and §7.6.4.2 (Table 21, R); ISO/TS 32003. Aes256 is the PDF 2.0
algorithm and Aes256Gcm its ISO/TS 32003 extension; the others are deprecated in PDF 2.0 and are written only when
chosen explicitly, for readers that predate AES-256, with an EncryptionDeprecated diagnostic.
kind:method, kind:property, kind:ctor. Press Esc to clear.Aes128Deprecated: AES-128 in CBC mode with a 128-bit key derived from the user password: V 4, revision 4, crypt filter method AESV2. PDF 1.6.Aes256AES-256 in CBC mode with a random 256-bit file key: V 5, revision 6, crypt filter method AESV3. PDF 2.0.Aes256GcmAES-256 in Galois/Counter Mode with a random 256-bit file key: V 6, revision 7, crypt filter method AESV4. PDF 2.0 with the ISO/TS 32003 extension, which the save declares in the catalog's Extensions (ISO_, level 32003). Every string and stream carries its own authentication tag; few readers support it yet.Rc4Deprecated: RC4 with a 128-bit key derived from the user password: V 2, revision 3. PDF 1.4.