Top 128 Bit PDF Encryption Software
Various PDF encryption options are available and here are three of the best: VeryPDF, PDF-Convert and A-PDF.
Using 40-bit or 128-bit encryption to apply passwords and set permissions to existing PDFs, VeryPDF can be used to prevent printing of documents by unauthorized readers, although the source document must be an unencrypted PDF. Copying of text and graphics within the PDF document can also be blocked, making VeryPDF a good choice with plenty of options.
Licenses for VeryPDF begin at $38.00, with lower prices available for bulk licensing. Visit www.verypdf.com/encryptpdf for more information.
PDF Encrypt Tool v2.00
An alternative to VeryPDF is PDF Encrypt Tool, which also supports 40-bit and 128-bit encryption. Again offering passwords that can prevent printing of the document, this particular utility is particularly flexible in terms of your operating system - you can even install it on a Windows 95 computer providing the PC has over 32MB of memory.
A trial version of PDF Encrypt Tool is available for you to try out, allowing up to 30 encryptions. Visit www.pdf-convert.com/pdf-encrypt-tool/index.htm to download or purchase for $29.35.
Making full use of the fact that A-PDF will encrypt a document for a fraction of the price of the full Adobe Acrobat software, A-PDF includes support for 40-bit and 128-bit encryption, user accounts and specific permissions. Additionally, documents can be set to expire after a pre-determined period of time.
A trial version of A-PDF is available free from the website at www.a-pdf.com/security/password.htm, while a full license can be purchased for $27.