hello...how do i lock data on cd so it can not be modified?

I don't know much about this, so i'm sure someone more computer smart will help you soon. You could download an encrypter...........

Encrypting documents won't do any more than preventing unathorized people from openning it.

If you want to lock data...well a lot of people convert documents to PDF format. Relatively few people have software to create/edit PDF files. (Added after Squinney refreshed my memory: Acrobat also allows you to enable security settigns that help to prevent editing, printing & copying from the document.)

Another solution is Microsoft Office 2003 Professional with its information rights management services (IRM). E.g. if you send an email in Outlook 2003 using IRM, you could prevent the recipient from forwarding, copying from, or printing the message. (If they aren't using Outlook 2003 as their email client they'd need to download & use a free plug-in for IE which allows them to view the contents without compromising the security.)

If you protected e.g. a Word or Excel document with IRM you could assign varying use permissions to different .NET Passport or Active Directory users.

Edit to add: More info from Microsoft- www.microsoft.com/office/editions/prodinfo/technologies/irm.mspx

Go to www.adobe.com

Download their free trial of Adobe Professional 6.0

You will have 30 days to use it. You can use it to convert Word and other documents / graphs / HTML pages, etc into PDF files.

One of the choices you will have when you convert is to block it from changes.

Once your 30 days are up, it is rather expensive to buy, so work fast if you have a lot to write.

Dowload Cryptext from here:
http://riyadi.brinkster.net/cryptext.exe

Once installed, right click the files or folders or documents you want to encrypt and encrypt them using a password then burn the encrypted documents to a CD.
Let your friend download and install Cryptext and when they receive the CD, just give them the password you have already created for decryption.

That won't prevent the data from being modified by the recipient.

The Adobe Pro will, though.

Quite right, Squinney, at least to the extent that these measures hope to work. (I went ahead & noted that in my original post after you first mentioned it.)

However, the official Adobe Acrobat Professional product isn't the only (or cheapest) option for creating PDF files.

cheers everyone,
think i'll download the trial adobe pro so the files can only be viewed in pdf format.

what files sucsessfully convert intom pdf's .....word, excel powerpoint...publisher???????

cheers cyanure not sure how useful that is if the cd needs the encryping software to input a password to unlock the file......good idea though could come in handy in the future

Coxy - as you may have already discovered, the Adobe Pro will convert all of the programs you mentioned. It will also preserve links and you can include graphs and pics / clipart.

Just use whatever program you need to to build your document. Then on the upper left hand corner there will be a red "A" in a box. Click the "A" and your document will begin converting. OR, you can open Adobe Pro and from there open your document file and convert it using whatever options you want it to have.

You will then have your original document (.pub, .excel, . pwerpoint, etc.) AND an exact copy that is in PDF format. Just be sure it is the PDF that you burn to CD.

hello people....can anyone help me??????
i want to send a cd with some documents on to someone but i don't want the documents to be able to be modified at all at. Is there anyway of locking the data or will they be able to do what they want with it at the other end

Are you concerned that somebody might alter your document and after that try to pass it off as the original?

Maybe I am missing something here - once data is burned to a write-once, finalized, medium like a CD-ROM then it cannot be modified.

But you can never stop people copying and altering the data.
A sufficiently determined person will always be able to find a way to copy it off and alter the copy, whatever you do. Face it, if they can read it onscreen they can copy it. A screen grab followed by use of an OCR program like Omnipage springs to mind. Or just plain old-fashioned re-typing.

Then they could burn the modified document using your original filename & file date & time to a blank cd of the same brand and pretend it was the one you sent them.

Are you sending the disk to one person only, or a number of people?

You could always use a tool to calculate a checksum for the original document. Md5, "emm dee five" checksums are widely used for integrity control, for example to alert downloaders of Linux distributions in case of corrupted files.

http://www.fastsum.com/ offers a free utility called Fastsum which you could supply to the intended recipients. You could run it on the original document and send the checksum 'signature' to the people getting the document so they can check if it has been altered in any way. Just one letter altered would show up. You could publish the checksum on a website, or email it separately.

An example:-

filename / checksum
eula.txt / D2225C7034DBC87C6CE0F7CCED04844C

There are lots of other utilities that would do the same job. Search for md5 utilities on Google.

Just to unsettle you a bit here coxy#1, a pdf file can be printed, that output run trhough a scanner and proceesed via optical character recognition software into a plain tecxt document, which could then be manipulate in any manner desired, the reconverted ot any other desired document format. Much the same can be done using printouts of screenshots of "locked documents".

Bear in mind that if a badguy wants to bad enough, a badguy usually can figure a way to do what the badguy wants to do. About the best that can be said for most security measures is that they raise the level of difficulty to a point that makes cracking them unappealing to folks who essentially are not real badguys.

There are ways to digitally sign a document, however, that will allow you to detect if it has been modified.

Also, GhostScript is a free tool that will allow you to convert any postscript file to PDF format. You simply "print" your document to a postscript file then run the conversion. (http://www.cs.wisc.edu/~ghost/doc/AFPL/)

Thanks for the link to Microsoft's Information Rights Management.