PDFBlackbox (VCL) Version 5.1

PDFBlackbox (VCL Edition) is a comprehensive collection of native components that help you compress, encrypt, sign and compress PDF documents from your Delphi or Kylix applications. Both symmetric and certificate-based (X.509) encryption and signing is supported.
PDFBlackbox supports full range of PDF security operations, including
* PDF standard password-based data encryption using MD5 + RC4/40 or RC4/128 algorithms;
* PDF certificate-based public key data encryption using RSA algorithm and PKCS#7 format;
* certificate-based data signing using SHA1 with RSA algorithms and PKCS#1 or PKCS#7 format;
* support for cryptographic hardware (USB cryptotokens and smartcards)
* ZLib compression;
* stream-based processing, which lets you handle huge amounts of data without significant memory requirements;
* support for PDF format versions 1.3 to 1.6
PDFBlackbox components are a clean-room implementation of PDF format specification, which don't use any third-party libraries for core functionality.
VCL edition of PDFBlackbox can be used with Delphi 4-7, 2005 and 2006, Kylix 3, FreePascal.