• Home
• Blog
• Downloads
• Info
• Reviews
• Virus Warnings
• Search Site

Password Protecting a PDF File in Adobe Acrobat

Acrobat supports public/private key encryption, but if you don't have a security certificate for another party to whom you are going to provide the encrypted document, then you need to use the "shared secret", i.e. password, approach for encrypting a PDF file where you specify a password for the document and give that password to the other party by some means other than email, e.g. by phone.

You can use the method outlined by Adobe in Set passwords for PDFs to password protect PDF files that you will then email to others.

The article mentions that PDF documents can have two types of passwords:

1. User, aka "document open", password
2. Pemissions, aka "master", password, which provides access controls for the PDF document

To keep unauthorized individuals from viewing a PDF file, employ a "user" password. The other type of password, which you might also want to use in some cases, controls what recipients can do with a document.

Note: there are low-cost tools readily available online to remove that type of password from a PDF file. There are also low-cost programs readily available to defeat the first type of password unless you pick a strong password, i.e. one that is not a dictionary word, car name, sports team, person's name, etc. There are plenty of password dictionaries available to allow people to crack weak passwords. Any password protection scheme is virtually worthless, if someone picks a weak password. A strong password should have at least 8 characters with a combination of characters from at least 3 character sets. Character sets include those below:

1. Upper case letters
2. Lower case letters
3. Numbers
4. Special characters, such as "!", "-", "_", "$", etc.

Open the file you want to protect in Adobe Acrobat and follow the instructions below for encrypting and password protecting the file.

1. Click the secure button in the Tasks toolbar and choose Password Encrypt.
2. Click on Yes when prompted "Are you sure you want to change the security on this document?" If necessary, type the Permissions password that lets you change security settings. If you don't know the password, contact the author of the PDF file.
3. In the Password Security - Settings dialog box set the security options as desired. For the Compatibility setting, "Acrobat 5.0 or later" is the default option. That will provde 128-bit RC4 encryption. Selecting "Acrobat 3.0 or later", instead, will mean that users of older versions of Acrobat will be able to open the file, if they know the password, but I would strongly advise against choosing that option, if you need to guarantee that only someone who has been given the password can open it. If that option is selected, a 40-bit encryption scheme is used instead of 128-bit encryption. Even with a strong password, if you use 40-bit encryption, there are plenty of low-cost programs available online for anyone to easily break the password protection. With 128-bit protection, you can be confident that the protection will likely remain unbreakable for years to come (eventually increases in computing speeds, or the development of quantum computers, will likely render even that level of encryption breakable).
4. Specify a password, click OK and then OK again.
5. Save the file

Note: these instructions were written specifically for Adobe Acrobat 8 Standard edition, but will likely be similar for other versions.

[/os/windows/software/pdf] permanent link

PrimoPDF Producing Zero Byte Files

I installed PrimoPDF 3.0 on a system. PrimoPDF provides free PDF converter software that will allow you to "print" documents to a PDF file. After installing the software, I could print to PDF files without a problem from the administrator account from which I installed the software, but when I printed to a PDF file using the PrimoPDF "printer", I would receive the error message below:

Adobe Reader

Adobe Reader could not open 'http.pdf' because it is either not a supported file type or because the file has been damaged (for example, it was sent as an email attachment and wan't correctly decoded). OK

When I checked the PDF files produced by PrimoPDF, I found they were always zero bytes in size. When the files were being produced I would hear an error beep.

An Error after converting posting at the PrimoPDF Forums, suggested giving the Users group on the system full control of the directory into which PrimoPDF is installed.

From the Windows Explorer, I right-clicked on the directory under Program Files into which I had installed PrimoPDF and chose Properties. I saw that the Users group had only read access, i.e. only the read & execute, list folder contents, and read permissions were granted to the Users group for that folder.

Note: you can use the cacls command to check permission from the command line, e.g. cacls "\program files\primopdf", if the installation directory was \program files\primopdf. You will see BUILTIN\Users:(OI)(CI)R. The R at the end indicates that the Users group on the system, to which all normal user accounts belong, has only read access to that directory.

If you are logged into an account that is a member of the Administrators group on the system, you can right-click on the directory and choose Properties to reset the security permissions. Click on the Security tab, then select the Users group under "group or user names", then grant Full Control.

Since I was logged into a normal user account at the time I encountered the problem and had a lot of windows open and didn't want to have to close all of them, logoff, logon as an administrator, logoff, logon to my user account again, and then reopen all of the applications and files I previously had open, I used the cacls command to reset the permissions. To use that method, you need to take the following steps, if you are currently logged into an unprivileged user account.

1. Open a command prompt window as the Administrator. On Windows XP systems, you can do so by going to C:\WINDOWS\system32\ and right-clicking on cmd.exe while holding down the shift key (if you don't hold down the shift key at the same time, you won't see the "run as" option). Then select Run as. Click on The following user and put in Administrator, or some other account with administrator access, for the user name, and enter the appropriate password. Then hit Enter or click on OK. A command prompt window will open with Administrator credentials.
2. Enter the command cacls "\program files\primopdf" /E /G Users:F to give all users of the system full control of the directory where you installed PrimoPDF, presuming that you installed it in \program files\primopdf. Granting full control of the directory means they can add or delete files in that directory. The Users group will still only have "read" access to the dll and exe files in the directory, though. The /E means "edit the existing Access Control List (ACL) rather than creating a new one and the /G grants access for the account or accounts specified as a parameter. The F at the end grants "full" access. You can enter cacls /? for help with the cacls command. You will see something like "processed dir: C:\program files\PrimoPDF", if the command is successfully executed.

[/os/windows/software/pdf] permanent link

Print Last Page First in Adobe Acrobat

To reverse page printing order, i.e. to print the last page of a document first, in Adobe Acrobat 6.0, take the following steps:

1. Click on File.
2. Select Print.
3. Check Reverse pages.



4. Click on OK.

References:

1. Options in the Print dialog box
   Adobe Systems Incorporated

[/os/windows/software/pdf] permanent link

Printing Problem for Excel Workbooks with Multiple Worksheets Using Acrobat

If you are experiencing problems printing all of the worksheets in a Microsoft Excel workbook to one PDF file using Adobe Acrobat, the problem is likely caused by a variation in the "print quality" setting for the worksheets in the Excel workbook.

You can verify this is the source of the problem by clicking "File", then selecting "Page Setup" in Excel. With the "Page" tab selected, you will see the "Print Quality" setting for the currently selected worksheet. Let's say it is "300 dpi". But if you select the second worksheet titled "Page 2", when you take the same steps to view the print quality setting and don't see the print quality specified or it is different, then the variation in print quality settings is the source of the problem.

When the print quality settings vary between worksheets in the workbook, Adobe Acrobat will attempt to create multiple PDF files, one for each worksheet in the workbook, which is why it will prompt you multiple times for a file name. If you enter different filenames at each prompt, it will put each worksheet in a separate file.

To rectify the problem, make the print quality settings the same for each worksheet. In the case above, you could specify a print quality setting of 300 dpi for the "Page 2" worksheet as well.

You can change the print quality settings one by one for each worksheet in the workbook or you can select all of the worksheets at once by holding down the Ctrl key while clicking on the tabs at the bottom of the Excel window for the other worksheets one by one to select all of them, if you are working on a Windows system (you would use the Shift key on an Apple system). When all the worksheets are selected, you can release the Ctrl key then click on "File" and "Page Setup" to specify the print quality settings for all of the worksheets at once.

The minimum dpi for a laser printer is normally 300 dpi and is probably adquate for most spreadsheets you will print. Adobe uses 600 dpi as the default setting for Adobe Acrobat and Distiller and recommends that setting, but you can make the setting whatever you like. The output you will get when printing will depend on whether the printer selected can actually support the dpi value you've selected, though.

Once, you have set the print quality settings to be the same for all worksheets, take the following steps to print the workbook.

1. Click on "File".
2. Select "Print".
3. Select "Adobe PDF" as the printer.
4. In the "Print what" section, select "Entire workbook".

You should now have one PDF file containing all of the worksheets.

References:

1. More than one PDF file is created from an Excel workbook (Acrobat 5.0-6.x on Windows or Mac OS)
   Adobe Systems Incorporated

[/os/windows/software/pdf] permanent link

Acrobat Crashes Due to Too Many Temporary Files


If Adobe Acrobat crashes as it is opening the problem may be due to too many Acrobat temporary files. I've observed this problem with Adobe Acrobat 6.0 and I believe it is present in other versions as well. The following procedure should correct the problem:

• Click on "Start".
• Select "All Programs" or "Programs" depending on your operating system.
• Select "Accessories".
• Select "Windows Explorer".
• Double-click on "My Computer" in the left pane of the window that opens.
• Double-click on drive "C:".
• Double-click on the "Documents and Settings" folder.
• Double-click on the folder that matches the username you use to log into your PC. If you don't find an exact match, you will need to pick the one most likely to hold your data.
• Double-click on the "Local Settings" folder. If you don't see it, then you will need to change Explorer's configuration to display hidden files. You can do so by clicking on "Tools", then "Folder Options" and then "View". Under "Hidden files and folders", check "Show hidden files and folders" and then click on "OK". You can put the setting back to its previous setting after you have finished this procedure.
• Under the "Local Settings" folder, double-click on the "Temp" folder. If the files are not sorted in alphabetical order by file name, click on "Name" at the top of the Name column to sort them by file name.
• Scroll down until you see files that begin with the name "Acr". The type should be "TMP file". Click on the first one to highlight it. Then scroll down to the last one and, while holding down a shift key, click on it. Now all of the temporary Acrobat files should be created. These are files that are only needed temporarily by Acrobat, so they are safe to delete.
• Right-click and pick properties. The number of files you have selected will be displayed. If you see over 65,535 of these files, the large number of files is likely your problem. Click on "OK" to close the Properties window.
• Right-click again, while all of the files are still highlighted and select "Delete". When asked if you wish to send all of the files to the Recycle Bin, choose "Yes". If you hold down the shift key, while clicking on "Delete", the files won't even go into your Recycle Bin, where they could be recovered, but will instead be permanently deleted, which is probably a better option in this case, since you shouldn't ever need to recover them.
• If you changed Explorer's configuration to display hidden files, you can now put it back to what it was before by clicking on "Tools" and going through the procedure outlined above to change the way Explorer deals with hidden files. If not, you can just close the Windows Explorer window.
• Reopen Acrobat. If the cause of Acrobat crashing was too many temporary files it should now open without a problem.

If the problem still exists, look for Adobe Acrobat temporary files in the Windows temporary directory as well. This will likely be c:\windows\temp or c:\winnt\temp.

[/os/windows/software/pdf] permanent link

Reducing the size of a Portable Document File (PDF) file in Acrobat 6.0

To reduce the size of a PDF file in Adobe Acrobat 6.0, take the following steps:

1. Click on File.
2. Click on Reduce File Size.
3. Select the desired compatibility. You have three options:
   • Adobe Acrobat 4.0 and later
   • Adobe Acrobat 5.0 and later
   • Adobe Acrobat 6.0 and later
   Selecting a later version will allow a greater reduction in file size, but will necessitate others viewing the file to have that version. Selecting an earlier version will provide greater compatibility, but a smaller reduction in file size.

When you are working with a PDF file, you can also reduce the size of the file by choosing Save As and then overwriting the file you opened. When you choose Save As, Acrobat will save the file as efficiently as possible, whereas when you choose Save, changes are appended to the file, which may make it larger. Acrobat will also optimize a document for "Fast Web View" when you use Save As, allowing the document to be downloaded one page at a time from a Web server, which will reduce the time it takes to view it.

You can see the size of the file in Acrobat by clicking on File and then Document Properties. Under the "Description" section, in addition to the file size, you will also see the PDF version listed, which will tell you what version of Acrobat others will need to view the file.

References:

Reduce PDF file size

[/os/windows/software/pdf] permanent link

Feature Comparison Between Adobe Acrobat 6.0 Standard and Professional

A chart is available at http://www.adobe.com.au/events/roadshows/pdfs/FeatureComparision.pdf comparing the features found in Adobe Acrobat 6.0 Standard and Professional versions. The chart also covers Adobe Reader 6.0 and Acrobat Elements 6.0.

[/os/windows/software/pdf] permanent link