Posted: Tue Jun 02, 2009 8:23 pm Post subject: NeoOffice to eBook?
Back again after getting straightened out on digitally signing a NeoOffice document -- thanks again -- but with an OT inquiry.
I'm getting close to a final draft of an eBook to be available free (license CC [BY,NC,SA]) that I want to make available for download in a pdf like format that I can authenticate and reflect the integrity of the original with a digital signature. That is, I just want to protect it against misrepresentation of the content. I've been writing with a book drafting application, then formatting the text and images into a desired presentation with NeoOffice. I originally thought I would just export to pdf, but can't seem to protect such (digitally sign) without undue expense. [already spent more than I should have on obtaining 90 some research papers to be sure of their content].
So, in the vast experience of this audience, are there any suggestions on a presentation file format I could use where 1) readers could easily obtain a free reader on any platform, and 2) that I could reflect the authenticity of the file downloaded with a digital sig?
Any thoughts would be greatly appreciated, as I should be spending more time on the final draft than researching this point
Joined: May 25, 2003 Posts: 4752 Location: Santa Barbara, CA
Posted: Tue Jun 02, 2009 9:48 pm Post subject:
Well, if you're looking just to be able to provide a way for people to verify that a certain PDF has not been modified and, assuming you have your own website, you can just post an MD5 sum. An MD5 sum is a cryptographic hash that is unique for most files; a small change in the file will cause the hash to be different. Users will need to manually verify the MD5 hash of what they have against what's on your website.
You can generate MD5 hashes from a Terminal using the "openssl md5" command. SHA1 hashes are also an option, but MD5 should be sufficient.
For things under creative commons license that's probably the best you can do; if you're trying to restrict distribution in a way where you want to guarantee people can only get it from yourself you'll probably want to use a different license or use an online only distribution system that you can control (like scribd).
Posted: Wed Jun 03, 2009 6:11 am Post subject: RE: NeoOffice to eBook?
Thanks Ed,
Hadn't thought of just posting the hash, and it would suffice if any readers bothered to generate such for any copy they received and compared it with the posted hash on my site -- in which case they could have just downloaded the book from my site in the first place I guess. Although, I'd like the book to be distributed from any site that thinks it worthy, and the receiver to have some readily apparent way of effortlessly "seeing" the integrity of the content.
The whole point of a digital sig is authentication (source identity) and content integrity (internal hash) that can be seen in the form of some little icon in their reader -- thus being readily seen without any extra effort. Obviously one can do such with a NeoOffice file, but there's no freely and widely available "book" reader for such that I know of (maybe a hint). It just p's me off that such is made so costly for pdfs, so I'm searching for an alternative (an underlying polite thread of the book is industry manipulation, so you might understand my mindset).
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of this audience, are there any suggestions on a presentation file format I could use where 1) readers could easily obtain a free reader on any platform, and 2) that I could reflect the authenticity of the file downloaded with a digital sig?
