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The ABCs of the PDF: G-I

Veering away from XPS this week, I’ve got the next posting in the ABCs series for you. It’s been a while, but here it is. This week, it’s about the history, the mechanics and the product. A little vague? What does this have to do with the PDF?, you ask. Read on.

GUI

From creation to manipulation and accessibility to view-ability, the GUI’s function is crucial to working with PDFs. Yet have you ever wondered about the history behind the interface you use? The first rough idea of a GUI was conceived of by American engineer, Vannevar Bush (1890-1974) in the early 1930s. In his essay “As We May Think,” published in 1945, Bush describes a device he called the “Memex” that would transform physical gestures into technical commands. A user could call up and display multiple “book” files on a desktop screen and jump through pages of content with the movement of one’s hand. Yet, it was only theorized about until Douglas Engelbart (1925-2013),  inspired by Bush’s idea, decided to develop and implement the idea into a prototype. In 1968, the first working GUI was demonstrated.

The first marketable GUI using computer was invented by Xerox PARC in 1973 with the Xerox Alto computer. It was further enhanced by Apple’s revolutionary Apple Lisa PC ten years later in 1983. And by the 1990’s, the GUI of Microsoft’s Windows OS improved the functioning of the GUI into the one you know today. Of course, the interface has also been developed and used by a number of individual computer companies over the years, and it has come a long way in terms of looks and usage.

The goal for the GUI nowadays is to provide the most functionality within the least amount of space. And Adobe Reader 8 is just one example in its simplicity. Perhaps in the future our PDF viewers will do away with the GUI altogether, and use virtual reality as a way of “handling” PDF documents!

Hash Function

So far, we’ve made it so that electronic docs would be an easy way of storing and recording data. In addition, it prevents data from being physically lost or stolen– invisible and intangible until opened and printed. Yet, that also means that security has transferred from playing a physical role to a digital one. And just as you need a sense of security when physically locking doors, you also need it when securing electronic documents.

You already know that information security is important to the PDF and can be done with the click of a mouse. Yet, one of the things behind that simple move is something called a Hash function . Hash functions or algorithms play a role in creating a digital signature which you’ve undoubtedly used in the past to secure your PDFs. It is that digital signature which is made up of a hash and encryption key.

A textual message or document is made into a smaller data version of itself through a “hashing” process. When this happens, the content of the message is encoded, using a hash function. The hashed version of the message is called a message digest, which is, in turn, encrypted with the author’s private key. The resulting encryption of the message digest is the digital signature that you attach to the original PDF Document. All of this is done behind that one deceptive click.

And although the term “hash” may seem a funny word to refer to a security/encryption element, according to definition sources, it caught on in the 1960’s because it described the way in which hashing algorithms work—they “chop and mix” up the data being secured.

Investintech

The ever changing nature of the electronic world is not a new concept. Software and gadgets continually evolve within the fast paced environment of technological innovation. And Investintech has also been caught up in that forward momentum with the recent release of Sonic PDF Creator v.2.0. And, with its more-advanced-than-v.1.2 features (support for more formats, document toolkits and formatting capabilities), you can now create better PDF documents than you did before.

Of course, we’ll aim to surpass this 2.0 version in the future as well and continue to push the PDF creation envelope. It’s just a matter of checking in frequently to see what new creation features we’ll have in store!

‘Til next time. Stay tuned!

The ABCs of the PDF: D to F

The holidays are over for this year and it’s time to get back to work—and back to learning. Here’s the second posting on the ABCs of the PDF and, as promised, a few tidbits behind the day to day elements you use in your PDF work.

Data

The most important thing about a PDF is the data— its printability, its transmission and its integrity. Of course, this last point is the driving force behind the inability to edit PDF content, a quality with which the PDF world is familiar.

There have been notable rants and raves about this and, consequently, about the “usability” of the PDF format, citing issues such as document size and on-screen behaviour as annoyances. And yet, there are strong arguments defending the PDF and the working needs it fulfills with its “set-in-stone” data.

What do we make of this PDF usage debate? What’s the bottom line for PDF users, makers and shakers?

Fantasy: digital documents that aren’t easily manipulated by malicious users.

Reality: file integrity and data extraction go hand-in-hand with the PDF format. The only way to change or work with the data is to extract (aka “convert”) the content.

Conclusion: when working with a PDF, work with conversion in mind —which conversion software is practical for daily use, which format conversions you need, what kinds of PDFs you’re working with (scanned or native), what security features restrict the data you need, etc.

Encryption

And speaking of security, you’ll more than likely encrypt the PDF documents you create yourself. So, here are a few knick-knacks surrounding the encryption you’ll use:

• You may see the word “bit-encryption” when creating a PDF. Bit-encryption, which secure your documents, is based on the use of binary digits

• The higher the bit-number, the more secure your files are because of the increased probability of possible decryption keys. A 128-bit encryption, for instance, has a key length of 128 bits long, meaning that there 2128 possible keys

• Sonic PDF Creator v.1.2 includes 40- and 128-bit encryption

• The DES (Data Encryption Standard) was based on 58-bit encryption and adopted by US Federal government in the 1970’s. The current AES (Advanced Encryption Standard, 2000) is based on the RijnDael algorithm which makes use of128- to 256 -bit keys. It was adopted after winning a 3-year competition against other algorithms

• The concept of the computer, in fact, was based upon “cracking codes.” It was developed during WWII while trying to decode encrypted messages through the use of an “Enigma” machine

Fonts

As a PDF user, you know that part of maintaining the document’s appearance is retaining the textual font within the PDF. Yet, there is more to fonts than just a pretty face.

• There are about 20 components in the anatomy of a letter that define one typeface from another

• There are 3 different types of hyphen/dashes and, of course, vary in usage— and in look, from typeface to typeface (Three? Yes, three. Who would’ve thought?)

• Which fonts are best used for on-screen (PDF) presentation?

• The fonts used in a document affect the way you read the textual information. Serif fonts help to guide a reader’s eye along the lines in large blocks of text. Thus, Times New Roman, for instance, is generally used for printed text. Sans-serif fonts are used ideally for on-screen text because it presents a legible rendition on-screen

• Do you know the history behind the letters and fonts you use in your PDFs?

Hopefully, next time you read or create a PDF, you’ll look and think differently about the extraction, the encryption and the fonts you use on a daily basis. And, who knows, with a little tinkering, you just might create that ultimate PDF!