Excel sheet for clocking in/out

So I don't like the idea of having all of their barcodes in the spreadsheet because:

a) they can accidentally scan the wrong name

b) they could intentionally scan the wrong name

I would (IMHO) have their barcodes on their badge or keyfob or whatever and then they scan that (a backup binder with all of their codes or electronically in a different spreadsheet could be available in case they forgot their badge/keyfob)

But since you have a BarCode font (or if not you can download one for free), I would create a Log sheet with 3 columns:

ID  Date/Time  In/Out

and on the top of the sheet have 3 cells: Date/Time (=NOW() ),  In, Out  each of them shown in the BarCode font

Then they scan the badge which should hopefully cause Excel to update the cell with NOW() so then they scan the Date/Time (i.e. NOW()) cell and then either the barcode for IN or the barcode for OUT.

Then elsewhere you can connect the ID to the people and their clock in and clock out times.

Here is an image of what I'm imagining but sure you could improve on it:

then in another sheet you can summarize each employee's times.