Going digital
Rapid development of digital technologies and electronic communication, availability of mobile PCs and smart phones, abundance of tools for creating documents or high-quality presentations coupled with constantly growing volumes of information and yearning for doing business more effectively leads to switching to electronic exchange of information.
Not only enterprises, but state organizations are introducing new electronic systems of docu-ments circulation. Online-readers of e-newspapers and e-magazines outnumber those, who still read print media. Some titles exist on the net only. Those who own PDAs prefer e-books and e-magazines over paper ones. For instance, more than 80,000 e-books can be bought at the Amazon online store.
Exchanging e-documents means compatible platforms, applications and software versions. Eve-ryone has faced a “can’t open the file” situation. What does a file recipient use – PC or Mac, Windows Vista or Windows XP, Microsoft Word or Corel WordPerfect? The solution is using a universal format, which depends neither on software nor on hardware.
What’s good about PDF?
Such format does exist. This is an immensely popular PDF (Portable Document Format) — cross-platform format for e-documents, designed by Adobe.
Documents saved as PDF files can be viewed on virtually any system. Though platform, operat-ing system, installed fonts or software may vary, a document with original text formatting, font settings, pictures or layout can still be opened, read or printed correctly.
PDF is widely used in publishing and printing, distributing e-versions of media, publishing reports, reference information or documents, and exchanging data. Google search results for PDF files amounts to 2 360 000 pages!
It is really important that the software needed to open a PDF is free (from Adobe or a third party). These figures show the popularity of PDF format: Acrobat Reader is downloaded from CNET Downloads for nearly 35 billion times per month.
Versatile PDF format has quite a number of extra features: easy browsing of large documents with a help of a cross-reference system; proper viewing of a document with handheld devices running Palm OS, Symbian OS etc; text availability for search engines; compact files (small file size) and – the feature we are most interested in – wide range of document protection methods.
PDF documents protection
Cui bono?
Let’s see who needs to protect a PDF document and why. Today’s world assumes that possessing information is a competitive edge. Leak of confidential data may cause direct financial harm to an enterprise, indirect losses of opportunities and other unfavorable or unpredictable effects.
Obviously, much attention is paid to data protection. IT Security is a rapidly developing branch of Information Technology industry. The easiest method of data protection is locking with a pass-word. One has an ability to set the password (to open and/or edit the document, or use particular features like hi-resolution printing) in most desktop applications, including Adobe Acrobat.
Proper document password protection should keep the balance between security and usability. When setting a protection to a PDF document, one should keep the following points in mind:
1. target audience (all users, or just a certain group);
2. version of Adobe Acrobat / Acrobat Reader available;
3. storage location or publishing location of the document (company web site, intranet, or printing-house);
4. data type (text, graphics, multimedia);
5. presumable usage of the document (viewing, filling forms, sending by mail, editing or reviewing).
PDF documents protection methods
Adobe Acrobat features two levels of PDF password protection. Protecting the document with access restriction (“owner”, so-called “security” or “master”) password does not affect a user’s ability to open and view the PDF file, but prevents user from editing (changing) the file, printing it, selecting te xt and graphics (and copying them into the Clipboard), adding/changing annotations and form fields etc (in any combination). Also, there are “open” (so-called “user”) passwords. If one is set, the file is encrypted with strong algorithm, and cannot be opened at all, if the pass-word or encryption key is not known.
Adobe Acrobat uses RC4 encryption algorithm (stream cipher, widely-used by various data pro-tection systems), while Adobe Acrobat 7.0 and upwards can also use AES (Advanced Encryption Standard). Originally, 40-bit encryption has been used, but version 5.0 and above uses 128-bitencryption, which makes it much more difficult to find a password (40-bit encryption involves 240 values, while 128-bit encryption involves 2128 values).
