When you hear the name Adobe Systems' Adobe Acrobat 6.0, you might first think of PDF files and a standard format for exchanging documents across platforms, but our readers apparently also like the product's encryption and digital-signing features because they voted Acrobat 6.0 the Best Encryption/Digital Signing Software. Acrobat 6.0's security features let you protect files with a password to prevent unauthorized users from opening and viewing sensitive documents; apply permissions with 128-bit encryption that control whether users are allowed to view, edit, comment on, sign, or print PDF files; and approve final documents with secure digital signatures.
Acrobat 6.0 also makes it easy to create, distribute, review, and archive PDF files from a variety of sources, including Microsoft Office and Microsoft Internet Explorer (IE). And Acrobat 6.0 lets you merge multiple documents and images into one PDF file, insert comments in the file, and manage comments from multiple reviewers.