2 Methods of encrypting PDF documents

In the Internet, cloud computing, cloud storage more and more application environment, information security is increasingly important, especially the daily we use the most documents. The security management of documents is a problem that every enterprise and everyone must face. At present, for the document database system-level security scheme, such as "File Safe" and some other application solutions, but for the security of the document itself is rarely involved, here we will continue to introduce some in PDF document format for storage and security distribution solutions.

1, in all documents saved format, PDF is the highest security performance, in addition to the advantages of the format itself, the PDF vendors to improve their software security has made constant attempts to protect the authenticity of documents, integrity and confidentiality has good results.

The first is password encryption, which is the most basic line of defense in a PDF document. This encryption method is an off-line encryption method, as long as the user entered the correct password to open or document permissions password can open the document. This encryption method is easy to use, the limitation is that his protection relies on a simple string of passwords, the password is compromised can not protect the effect.

Password encryption contains the password to open the document and document management rights, and the open password for the document can only be used to open the document. The document's owner permission password is a higher-level password that opens the document and can be used to edit permissions to modify the document. Document permissions can be divided into whether to allow printing, whether to allow modifications, enable copying text, images, and other content.

In particular, it is to be recalled that, since not all Third-party products support and comply with the various operational restrictions set by the "License password", recipients of third-party products may be able to bypass certain restrictions set.

The second form of encryption for PDFs is certificate encryption. This type of encryption is also an off-line encryption method. Using the PKI (Pubic Key Infrastructure) Asymmetric encryption algorithm, the public key certificate is used for encrypting, and the private key certificate can be opened when decrypting. If the document is compromised, it also represents the user's private key certificate being compromised. In order to facilitate the safekeeping of use, there are also users to the private key certificate into the U-key, the use of the need to insert U-key.

Both encryption methods are offline encryption mode, but also the most applied 2 kinds of document protection measures, at the same time, these 2 encryption methods have their own limitations, or there is the risk of information leakage, need to be combined with other document security measures.

2. For the security application of PDF documents, we have introduced the use of professional-grade PDF clients (such as Adobe Acrobat, or foxit Phantom) for password encryption and certificate encryption (search for PDF document encryption protection). This article will introduce another very important security application for PDF documents-digital Signatures:

The digital signature on the PDF document, so that the document has authenticity and legitimacy, often used in contract text, legal documents, government documents, business letters, bidding documents, bank documents, electronic medical records, etc., more widely used in the financial and commercial fields.

A PDF electronic document if you want to transmit as an electronic file, you need to be clear about two things: one is to confirm that the file is actually issued by someone, and the other is to confirm that it has not been changed during the transfer. A digital signature can achieve this, and a digital signature determines that the information is actually signed by the sender, because the sender's signature cannot be spoofed by others. The second is that the digital signature can determine the integrity of the information. If the file is tampered with, the value of the digital signature will also change, will not pass the authenticity verification. Below, take Foxit Phantom PDF Client as an example to introduce the application of digital signature.

1, Foxit phantompdf can be imported into the Digital ID card, of course, the user can be purchased from a Third-party digital signature service provider. Open Foxit Phantompdf the "secure" menu bar to select "Place signature", in the area where the document needs to be signed, select the area with the mouse's cross cursor, pop the "Sign document" dialog box, select "Info" in the dialog box, and select "Install Certificate" in the Certificate pop-up box. Follow the wizard prompts to install it step-by-step.

2, Import Third-party certificate method Two: Under the Security menu, select Digital certificate, select Import in the pop-up dialog box, and then select the certificate you want to import.

3, after the completion of the digital signature of the document, you can display the issuer, the reasons for the issue, the date of issue and other information. The figure below is a digital signature style for a person named "Cidny" and stamped in the document.

4, the document recipient received Cindy signed documents, you can verify the document, including the verification and display the document after signing the certificate after the third person's modification, whether it is the original valid document, so that the recipient can at a glance, full trust in the document.

5. Finally, we would like to specifically introduce the Foxit with a docusign online digital signature cloud service platform (DocuSign is an online cloud service platform that complies with relevant electronic signature laws and regulations and business processes in the United States, the European Union and other parts of the world, Documents signed through DocuSign have the same legal effect as handwritten signatures on traditional paper-based documents:

Foxit Phantompdf supports the digital signature of PDF documents through client Connection DocuSign platform, and completes the whole business process, such as document sending, recipient signature and return, confirming signature through client. Electronic files are not in the form of attachments in the process of sending messages, but are kept in docusign cloud storage systems.

As shown in the picture, the Foxit PhantomPDF6.0 version, the recipient after receiving the message, even if he did not have DocuSign account can also be signed, the link address in the Mail can let him in the docusign of the interface to complete the signature, can choose to recommend several signatures, you can create their own signature, click to confirm the completion of the signature. The recipient and sender can access the signed documents anytime, anywhere, or print them out for storage. In short, the upcoming release of Foxit PhantomPDF6.0 will provide a PDF digital signature from the client to the cloud integration to verify delivery of the excellent experience and services.

In a word, the digital signature technology based on public key cryptography can confirm the identity of the author of the electronic file, and guarantee the integrality in the process of transmission, and provide technical support for the credentials of the identity authentication. At the same time, the relevant regulations and policies for the digital signature of the legal effect of the determination, to provide a legal basis. The digital signature service based on PDF document will get more and more personal application in the application background of cloud computing.