PDFCreator Help |
Signing Signing PDF files enables the receipient to verfiy, that the document is from the proper person and has not been modified after signing. This is done with a private/public key mechanism. The private key is used to encrypt a fingerprint of the document (the hash). This can be decrypted with the public key and then be compared with a hash created from the present document. These only match, when private and public key match and the document has not been modified. To digitally sign a PDF, there are several requirements, that need to be met:
Pfx/P12 file: The file with the signature. It stores the private key which is used to encrypt the hash value. Signature reason: The reason for the cerfitifacte. This is a piece of text, describing, why the document is signed. Signature contact: The name of the contact person, that signed the file. Signature location: Place (Country, City etc.), where the file has been signed. Signature position: Allows to let Acrobat Reader show an icon showing the validity of the signature. The coordinates for this icon can be set with the LeftX/Y and RightX/Y values. You can also define the page on which the signature will be displayed. If set to a value below zero, it will be displayed on the last page. Multi signature allowed: Allows the PDF to be signed by other people afterwards. You can get free certificates at http://www.cacert.org. Please note, that this is not a register-and-go service. CACert is based on a web of trust, where you are verified by people and can verify other people. It takes a bit of work to get enough points for a trusted status, but it really is free and you should give it a try. |