Can Excel spreadsheets be made 100% 'hack-proof'? The quick answer is no. I think everyone in the world is still looking for that kind of security for a digital product!
However, you can use a couple of tricks that will confuse and discourage amateurs from tinkering with your workbooks.
However, you can use a couple of tricks that will confuse and discourage amateurs from tinkering with your workbooks.
Step 1: Protect Sheets & Workbook Structure With Office 365
Office 365 has silently introduced security changes in order to strengthen Excel worksheet & workbook structure protection. Use the latest version of Office 365 to protect sheets and workbook structure!
More details for technically minded readers:
To upgrade your protection to the latest secure hashing algorithm, as used in Office 365, even if you use Excel 2007-2010 or the perpetual license (one-time purchase) of Office 2013-2016, please use this Ribbon Commander powered add-in.
More details for technically minded readers:
- Read our article to learn why the new sheet protection algorithm in Office 365 is far more secure.
- Read our article to understand why sheet protection in Excel 2010 and prior versions are vulnerable to brute force attacks with VBA code circulating the internet.
To upgrade your protection to the latest secure hashing algorithm, as used in Office 365, even if you use Excel 2007-2010 or the perpetual license (one-time purchase) of Office 2013-2016, please use this Ribbon Commander powered add-in.
Step 2: Save Using Excel's Binary File Format
Save your files using Excel's binary (XLSB) file format, as most hacking utilities cannot remove worksheet or workbook structure passwords from binary files.
Read our article to learn the advantages of Excel's XLSB file format.
Read our article to learn the advantages of Excel's XLSB file format.
Step 3: Use Macros To Safeguard Protection
You need to add a couple of lines of VBA code to:
Obviously, this code won't run, if macros are disabled. So, you may need to force your clients to enable macros. Read how here.
- Prevent users from saving the workbook in a file format other than binary.
- Verify that sheets & workbook structure are protected during file-open.
Obviously, this code won't run, if macros are disabled. So, you may need to force your clients to enable macros. Read how here.
Step 4: Lock VBA With Unviewable+
Please protect your VBA code from popular hacks, such as hex editing.