How an encrypted document is protected and what the credential that opened it allows.
public sealed class PdfSecurity
ISO 32000-2 §7.6 (Table 20 and Table 21); ISO/TS 32003 (version 6, revision 7); ISO/TS 32004 (integrity MAC). Read once, when the document is opened; EncryptionDictionary is the live encryption dictionary.
kind:method, kind:property, kind:ctor. Press Esc to clear.AccessGets which credential opened the document.EncryptionDictionaryGets the encryption dictionary (the trailer's Encrypt entry), whose strings are never encrypted.EncryptsMetadataGets a value indicating whether the document-level metadata stream is encrypted (EncryptMetadata).HandlerGets the name of the security handler that opened the document, such as Standard.IntegrityGets the outcome of checking the document's integrity MAC when it was opened.KeyLengthGets the length of the file encryption key, in bits.PermissionsGets the permissions that apply: All for the owner, the granted ones for a user.RawPermissionsGets the user access permissions word as the document states it (the P entry, or the value in Perms).RequiresIntegrityCodeGets a value indicating whether the permissions require a PDF MAC token in every revision (bit 13 clear).RevisionGets the standard security handler's revision R (2 to 7), or null for another handler.SubFilterGets the encryption dictionary's SubFilter, or null.VersionGets the algorithm code V: 1 to 4 (deprecated), 5 (AES-256) or 6 (AES-GCM, ISO/TS 32003).