Encryption with password protection

When encrypting a PDF document with password protection, rights are grants which apply in equal measure to all recipients. The recipient decides whether the PDF document may be read, printed, processed, added to or copied. Here it is possible, in addition to the owner password with which all the granted rights can be managed, to optionally specify a password for opening the document.

Let’s look at this more closely using the example of Alice and Bob: Alice want to send Bob a PDF document, she also wants to assure that, firstly, this document will arrive unchanged and that, secondly, only Bob will be able to open it. She protects the PDF document from changes using her owner password and adds a further password for opening the file. She notifies Bob of this password via a secure channel. Now only Bob can open the document using the password. The PDF is symmetrically encrypted.

When is encryption with password protection expedient?

Encryption with password protection is the right choice when, for example, a PDF document is to be published in the Internet and should be accessible by a large number of people. Such circumstances make it difficult to demand a certificate from every user. The document can be protected in such a way that it cannot be changed by users without further measures being necessary. This method is also expedient if a large number of PDF documents are to be sent by e-mail, e.g. quotations, invoices etc, and the sender wishes to ensure that the contents of such documents cannot be easily changed.

In the case of extremely sensitive content, e.g. financial statements, certificate protection is strongly recommended.

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