I have a spreadsheet with sensitive data. How might I block a certain column from others users viewing it?
There is no way to securely block viewers or editors from getting viewing access to a range of cells. I.E. anyone having access to a spreadsheet could create a copy, this will make the copy creator the owner of it.
One alternative is to use two spreadsheets, one for sensitive data and another for non-sensitive data each of them with the proper access permissions.