Protection of Data

[Suec1909]

I would like to create a spreadsheet to pass order data which will include
credit card numbers between staff. The credit card numbers need to be as
secure as possible and access to them controlled by passwords, either on
cells, sheets or the entire workbook (or all three!). I had also thought of
only allowing a credit card number to be shown by a password controlled Macro
once entered... if that's possible and hiding it on password protected sheets
and similar ideas...

Has anyone done anything like this and could offer any help on ways this
might be achieved to the best effect?

Many thanks

Sue

 

[Luke M]

For the level of security you are requiring, DO NOT use XL's protect sheet
password. The passwords used to protect sheets and cells are very "weak" and
can be cracked by macros (easily found on the internet) within minutes. (Note
that this is handy for those who are forgetful).

The passwords used to open the workbook (not just in write-mode, but to just
open it for viewing), or view the VBA coding use a better encryption which
would require more advanced software to crack.

In short, I'm not sure there is a secure way of doing what you want to do,
unless you can somehow "hide" the credit card numbers within the macro, or
place them in a seperate, secure workbook that you could insure can't be
tampered with. Sorry this wasn't so much of a suggestion, but I wanted to put
the warning out just in case you weren't able to get a good suggestion.

 

[TGV]

Create it in Ms-Access and run the user lever security wizard. That's it
your problem will be solved.

TGV

 

[Suec1909]

Thanks for the responses... yes I appreciate what we're trying to do is not
ideal, the aim is mainly to improve what currently happens is that
spreadsheets are emailed with no protection at all - or details are sent in
emails without introducing a different system. Access isn't widely used so
wouldn't be ideal but I will check it out.