Excel Encryption Improvement?

[cadence]

Hello,
Is it true that Excel had finally improved its workbook/sheet & VBA protection for 2-bit encryption to 40-bit encryption?

Without wanting to get into a discussion about cracking it, is this proving to provide more security to documents or is it still easy to crack with your 3rd party add-ins?

Can anyone tell me if this is so, when opening an older format in excel 2007 does it apply the 40-bit encryption to it when saved?

thanks johnny

 

[SydneyGeek]

Doesn't make much difference. I tried it it 2007 on a .xls file. Took a minute or two instead of a few seconds, but it still isn't secure.

Denis

 

[cadence]

Thanks Denis

saves me doing the testing. what a disappointment, never understand why they can;t put a bit of encryption that is a little more secure.

Do you think they ever will?

Do you know anything about converting an excel file into a true stand alone application?

thank johnny

 

[SydneyGeek]

Thanks Denis

saves me doing the testing. what a disappointment, never understand why they can;t put a bit of encryption that is a little more secure.

Do you think they ever will?

Do you know anything about converting an excel file into a true stand alone application?

thank johnny

No, they won't as far as I know. Microsoft does not regard Excel as a secure platform. Therefore, it's unlikely they will try to make it one.

One way of securing the code is to write it in .NET, using the VSTO tools that MS developed. First, you need $1300. Then you need to learn VB.Net. Then you need to ensure that your users have the .Net Framework installed.

As for turning Excel files or code into stand-alone EXEs, I don't think there is a simple way to do it.

Negative thoughts aside, here's a couple more to think about:
1. The VB Project is better protected than the worksheet / workbook. The sample that I ran was to unlock a worksheet -- something I have had to do more than once when a client stuffed up and forgot the password. There are ways of cracking the VB Project password but they are harder to come by, so I think VBA code is reasonably secure.

2. You can secure files to a greater or lesser extent by doing one or both of the following:
a. Put the file in a secured network folder, so you limit access to the file in the first place
b. Set the file up so users see a single, blank sheet with a password prompt. The password can be appended to the file path of a different network file. The code looks for the whole result; if OK (the file is in its original location) they get to work with it. If not (it has been taken off the network or moved), the file closes. There are a number of password prompt examples around so I won't go into the details here.

Hope that helps

Denis

 

[cadence]

Thanks for the insight.
Its been a real struggle for me. Whilst I not real coder, I have developed a small industry based app that I would like to launch.

I hoping you might be able to shed some more light

I originally designed it cross platform, and now since office 08 has come out on mac that is no longer possible. The majority of my customers are mac based. And the users won't be on a network but rather on stand alone files that are authored to them.

The VSTO sound interesting, but that won't solve the mac side of things

Security wise its as tight as you can get it, I have a encryption code to that checks for validation before launching, but at the end of the day all anyone need to do is crack the VBA and its all over.

I don't know where to turn to so that if I want to make it a stand alone application i can do it, A for a mac and B cross platform [else a separate one for PC]

any ideas or contacts who I can approach to help develop?