Excel Unplugged

test = zzyw = BBAb

The title might make you think that I lost my mind, but this is actually one of the best tricks to show your colleagues and also a transparent demonstration that all versions of Excel before Excel 2013 were lacking a great deal in security.

Ok so as the introduction suggests, this will only work in Excels prior to Excel 2013. Here’s what you do, protect a Sheet with Password: test.

Excel Sheet Protection

Then choose the Unprotect Sheet command

Excel Sheet Protection

But instead of writing test as a password, write zzyw or BBAb. It doesn’t matter which one you write, either one will unprotect the Sheet! Like Frank Sinatra once said, ain’t that a kick in the head J

Now to truly understand this, you must understand Excel sheet protection. You can read about it in chapter 4.18.4 of this document and if you want to go into it even further, read this.

One Comment

  1. Petros says:

    Until Office 2010, Excel used the outdated SHA1 hash algorithm to protect our passwords. The length of the hash used is just 16 bits (2 bytes). Due to the short length of the hash, a lot of different passwords share the same hash. Read more:



Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.