PDFBlackbox VCL
... Both symmetric and certificate-based (X...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...VCL edition of PDFBlackbox can be used with Delphi 4-7 and 2005-2006, C++Builder 4-6 and Kylix 2-3...
