Partially Blocking Social Security Numbers

There is LITERALLY nothing you can do that cannot be overcome with trivial efforts. As long as A file with the full SSN exists, no chain of effort, even involving VBA, can keep someone from locating the information and getting it.

Even with a user-facing spreadsheet opening a master spreadsheet (with layers in between for no useful reason, if desired) via VBA for the seconds it takes to update a user-facing data table and a password to open it, or something in between... all of it takes trivial effort to find each piece and do it yourself.

A file that cannot be opened... that'd work, but is of no real use, eh?

And I do mean TRIVIAL effort.

Not even to mention that other programs do not have to respect any aspect of Excel file security. And DON'T. Won't swear you can today, 'cause I haven't tried it recently, but up till a couple years ago in my personal experience, Google's spreadsheet would open any Excel spreadsheet regardless of protections.

Examining formulas in the XML file that is really saved is barely past the "trivial" level, but only barely. So while you might keep FORMULATEXT from revealing where a cell's formula looks to, you still can't keep the information from being seen by the simple expedient of looking in a file with a text editor. Nothing more required and all the protections are gone.

The orientation of Excel is the user of the moment matters and very little else does. This makes sense, even to a person like me who holds MS/Excel's feet IN the fire whenever possible. But that means the writer is only of primary importance while writing the spreadsheet, never, ever past that act. Nowhere is this more obvious than where security of anything in Excel is concerned.

If you include full social security numbers in anything user-facing, anything at all, you need fined by the government, disciplined by your employer, and sued by the employees. Outside of an HR network that is not connected to the internet or any network other than itself which actively scans your computer for activity trying to reach outside networks whilst you are on it, and that implements a virtual machine for your session anyway, I suppose.

Excel offers nothing more than, so long as a person is happy not to know or see things, it WILL let you arrange that. But for the &*^#'s that will delve, oh, just for the fun of it, not for any bad reason... there's nothing. Even a nice, climbable chain link fence with a lock on its gate offers more security than Excel.

Good tips, but it should be noted that businesses should NEVER, EVER store employees’ social security numbers in a spreadsheet. The risk and impact of a SSN breach is just too high - the convenience of spreadsheet analysis just isn’t worth that risk. Regardless of which Excel protection features you apply, any run-of-the-mill hacker could easily crack open the data, if the spreadsheet fell into the wrong hands (e.g., lost or stolen laptop). Keep SSNs in your HR system, and use another employee ID number for ancillary analysis & reporting. See the warnings on this page: https://support.microsoft.com/en-us/office/protection-and-security-in-excel-be0b34db-8cb6-44dd-a673-0b3e3475ac2d.