Excel: Safeguard Your Data
Updated: Apr 14
Microsoft Excel is undoubtedly the most widely used spreadsheet software in the market; counting the number of people who don't use it is probably faster than counting those who do. You're probably reading this post because you use Excel, which means you need to be aware of the security dangers in Excel and the steps you may take to secure your data and documents.
Excel’s Security Features
Like the rest of Microsoft’s widely-used Office 365 programs, Excel is one that hackers frequently use to launch attacks using Excel’s own tools. Malicious macros, another common attack vector, make their way into your documents when you open an infected document, which is why only opening documents from a trusted source is crucial. This is why disabling automated macros is an important element of protecting your Excel and Office files.
However, hackers should not be your primary concern. Instead, make sure you're familiar with Excel's features and aware of who has access to or can edit your data. If you've created a worksheet with sensitive data or formulas that you don't want anyone to modify, Excel has many tools to assist you to accomplish just that.
Nothing on our computers is 100% hack-proof, but these features can help you protect your Excel data from the more prevalent, easily preventable threats.
In Excel, you have three methods for protecting your data:
Though they may appear to do the same thing, they don't. Let's take a closer look at each type of protection to better understand the differences and choose which level of security you require in various situations.
This is the most common form of protection as it allows you to lock down your Excel file with the use of a password. Without a password, a user can’t open or modify the spreadsheet.
You have two options if you’re interested in using an Excel file security password:
Creating a password to open or modify a file: This option allows you to create a password that’s used to open or modify a file. It’s best for when you need to give others, such as co-workers or suppliers, edit or read-only access.
File encryption: This allows you to set a password and lock the file. This keeps others from opening it.
You can also do the following at the file level:
Mark as final: You can use this to mark your file as the final version, which prohibits other users from altering it.
Digital signature: Microsoft states that a “signature confirms that the information originated from the signer and has not been altered.”
Restrict access: This option works if your company uses Information Rights Management (IRM) to manage permissions.
It's crucial to remember that Microsoft won't be able to retrieve your password, so keep it safe (in a password manager, for example) so you don't get locked out of your own file.
Protecting a file only goes so far, as multiple freely available scripts can decode the passwords for older Excel versions. If you're concerned about the security of your Excel files, make sure you're always utilizing the most recent up-to-date software available.
A big part of your workforce planning strategy is designed around helping employees and departments work in a frictionless environment. When multiple people have access to an Excel workbook, you should consider locking the structure that you’ve created. This requires others to use a password to make changes.
For example, when you lock the workbook structure, other users no longer have the ability to add, delete or rename worksheets. This comes in handy particularly when you have multiple connected workbooks and you need to be sure that structure remains consistent across departments or teams.
Though the procedure for password-protecting a workbook is identical to that for password-protecting a file, keep in mind that the workbook is not the same as the file.
To protect the workbook, go to Review>Protect Workbook. Then, in the password box that appears, type a password of 15 characters or less. Select OK after retyping the password. Keep in mind that the longer your password is, the more difficult it is for people and machines to guess it. Passwords that are longer are more secure.
If you want to control how users use worksheets, this form of Excel security is best. It allows you to specify what a user can and can’t do, with the idea of keeping your data safe and as well as customizing the intended user experience.
For example, you may want to specifically prohibit users from using Sort and AutoFilter. They can still view the worksheet and do other things, but they’re prohibited from these functions. To "softly" secure your data, you might combine hiding rows or columns and apply for worksheet protection. This can be a convenient way to hide drivers and assumptions you may want to remain out of view.
To secure your worksheet, first, unlock any cells that you don't want to change. Select which tab you want to protect and which cells you want to be able to edit. Right-click anywhere and navigate to Format Cells. Deselect the Locked box on the Protection tab.
Then, under the Review tab, click Protect Sheet. You may select which components users will be able to alter from this menu. If you like, you can also enter a password, re-type it, and click OK.
Which Excel Security Protection is the Best?
This is a difficult question to answer. It all depends on your company, your function, and what you're attempting to achieve.
To keep your critical Excel files safe, the best thing you can do is learn the ins and outs of each sort of security. This will allow you to use the appropriate one at the appropriate moment.
Here are some general guidelines to get you started:
To manage user access, use file-level protection: For example, if you have a budget Excel file that you don't want anyone outside of your department to see, use file-level protection to keep it private. Because the file is encrypted, it requires a password to open it.
To govern how worksheets are used, utilize workbook level protection: A workbook with many worksheets is popular, for example, if you're a sales manager who needs a different sheet for each sales representative. This sort of security allows each rep to add data to their own worksheet while preventing them from changing any other worksheets in the workbook.
To regulate how users operate with individual worksheets, use worksheet level protection: It takes a long time to reformat worksheets over and over again. You can regulate what users can and can't do with this degree of security.
In a corporate situation, it's likely that you'll employ all three sorts of safeguards. Furthermore, changing protections is typical, such as when a new employee joins your department or when an employee is terminated.
Keep Security at the Forefront
Many organizations lean on Excel to store, track and measure data. While Excel is a powerful and secure tool in its own right, modern spreadsheet solutions have emerged in the last few years taking security to the next level.
Rather than constantly worrying about Excel security, select a solution that allows you to control data access and drill down into the history of a spreadsheet so you know who has been in your templates and where your numbers are coming from. Use this information to keep your data safe and secure at all times.