What?

The biggest challenge of a paperless office, or if you would accept all bills through email, a paperless household, is that paper is more pleasant to handle. Nobody likes to read lengthy texts from a monitor.

The solution can probably be found in the direction of electronic paper. This is a sheet that can display its contents without the back lighting that is required for a computer monitor. In effect, you are not staring into a lamp, but onto a bar that is quite like the notebooks that are used in Star Trek, either showing black&white or colour content.

The problem of reliability of paper has long been overcome; although paper is still formally acknowledged as reliable, computer science has developed technologie that exceeds the reliability of a paper signature by far.

The combination of such digital signatures with electronic paper not only make it possible to setup paperless offices, but such offices even become a pleasure to work in!

Why?

These devices equiped with electronic paper are known as e-readers. When properly implemented, their battery life is not expressed in hours, as is common with laptops, but in a number of page turns. On average, expect to get 8000 page turns from a single battery charge. Even if you read a lot, this means you will not be constantly recharging your reader device.

In addition, these e-readers are smaller and of lighter weight than their paper partners. Their storage capacities welcome complete libraries. And the screens work in environmental light conditions... including the Sun on a terrace!

Most e-reader document formats are compressed, to support a lot of text to be carried on a simple memory card. It is not exceptional to be able to carry 1000 books in your brest pocket. Or all internet standards. Or quite a selection from WikiPedia.

For paperless offices, compression matters. This is helpful in limiting the storage needed for older documents. In spite of compression, it is a general requirement that these documents should reproduce well, also when printing them. And archival software should use open formats, to avoid future format incompatibilities. Finally, digital signatures top off the archive with documents whose validity can be verified.

How?

The technology behind e-readers is based on bistable displays: een screen that can produce white or black dots, and possibly intermediate values like gray tones and colours, and keep that steady without a supply current. This is different from laptops, that constantly refresh the screen and that rely on memory that suffers from amnesia. Provided they are designed consistently, an e-reader can avoid these issues.

The devices interface with a host PC as plain storage devices, onto which a server can download all sorts of documents. It takes a bit of skill of the kind that is commonly for hire in the open source world to automate all sorts of document flows for any sort of business scenario.

Digital signatures serve to prove that particular content corresponds to a signature on the contents, if the signature can only be constructed by a party that watches carefully what it signs. The so-called signing policy of that party makes it possible to rely on certain facts about any document that has a valid signature attached. In case any changes were made in the document, the signature will fail and the document will obviously be unreliable. This is a great improvement on the simplicity of paper signatures!

Where?

• The manufacturer e-ink is known for its e-paper technology, just like Nemoptic, SiPix and Bridgestone.
• A few models e-reader are the Bookeen Cybook Gen3, the practically equivalent Jinke Hanlin V3 that also trades under lots of other names, the Amazon Kindle and Irex Iliad. The former two actually count battery life in page turns, while the other two add so much facilities like wireless access that their energy demand is continuous and so their battery life is expressed in hours. This poses a choice between usability in terms of longevity and usability in terms of facilities.
• Rather intruiging is that e-readers are sort-of cracked, by hackers with a positive attitude. (Hackers make things, crackers break things!) These people desire total control over their gadgets, and eventually they usually provide software of much better quality than the original firmware from the manufacturer. This is ongoing work in the OpenInkpot project.
• The DJVU (pronounced Deja Vu) format gives a highly compact storage format for documents. It is capable of presenting sharp letters with compressed background and images. Smart technology that uses knowledge of what we expect from a document, both in an e-reader and when printed on old-fashioned paper.
• Digital signatures can be constructed with X.509 certificates or, if it is to actually work well, with OpenPGP. The former is often mentioned in project plans, but it is by and large the latter that is actually realised in practical roll-outs, and is used in practice. It is a skill to setup any of these systems, but once installed it is not difficult to use.
• An example page shows that a simple 800x600 screen can suffice to display a normal document (in this case a technical specification) in 4 gray levels. In addition to this, it is usually possible to flip a PDF with much detail and view its upper and lower half as separate "pages".