Re: Encryption Used in Word 2004 for Mac

Hi Dan:

Oh? Is it urban myth time again? :-)

The algorithm in use is a 128-bit RC-4. The strength of encryption depends
upon the length of the password and its composition. But that applies only
if you set "Password to Open".

See here for more details:
http://support.microsoft.com/?id=822924

Mac Word and WinWord are equivalent, except that Mac Word does not have the
VBA code signing or Digital Signature facility.

As to your second question: Yes.

Files are not encrypted until you set "Password to Open" -- before then, the
entire file and all the temporary files and backup files are readable.

If you work on the document without a password and set the password at the
end before closing it, the temporary files (or some of them) will not be
encrypted.

It's good practice to reboot the computer after closing an encrypted file to
clean up the temporary files.

Note that an attacker would require fairly advanced knowledge to actually
access the temporary files: once you close the document they are
disconnected from it. An attacker would require an extended period of
access to the machine to get any significant amount of data back from them.

There is an element of "A lock will only keep out an honest man" to this.
If you need sufficient security to prevent people in the office reading
sensitive information, MS Office encryption will do the job nicely.

If you are expecting Level 5 intrusion attempts from organised crime or
nation states, then you better organise something a bit more secure :-)

Cheers

On 9/7/06 2:12 PM, in article
1152418378.813897.250510@xxxxxxxxxxxxxxxxxxxxxxxxxxxx, "starting over"
<zog.johnson.zog@xxxxxxxxx> wrote:

Hi,

I was wondering if anyone knew what kind of algorhithm was used for
file encryption by MS Word 2004 for Mac? How strong is it really?
Also, does Mac Office 2004 create readable cached files of encrypted
file that are recoverable from the hard drive?

Thanks,

Dan


--

Please reply to the newsgroup to maintain the thread. Please do not email
me unless I ask you to.

John McGhie <john@xxxxxxxxxxx>
Microsoft MVP, Word and Word for Macintosh. Consultant Technical Writer
Sydney, Australia +61 (0) 4 1209 1410

.

Loading