Enum PdfEncryptionStrength

Namespace

DocToolkit

Assembly

DocToolkit.Pdf.dll

The cipher used when a PDF is encrypted.

public enum PdfEncryptionStrength

Fields

Aes128 = 0

AES-128 (PDF 1.6). The default, because every PDF reader still in service can open it, and it is what the underlying library produces when nothing is chosen.

Aes256 = 1

AES-256 (PDF 2.0). Stronger, but it needs a reader that understands PDF 2.0 encryption — Acrobat X and later. An older reader cannot open the file at all, so choose this only when you know what will open the document.

Remarks

This is a compatibility decision, not a "more is better" one. Both options below are sound ciphers; they differ in which readers can open the result.