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Thread: Excel VBA: Hiding Code from End User

  1. #1

    Thread Starter
    Lively Member
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    Feb 2014
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    Question Excel VBA: Hiding Code from End User

    Hi all,

    I have a workbook that contains code which needs to be hidden or uneditable... preferably where nobody can get to it and see it.

    I have heard this is impossible with Microsoft's password protection, I have heard that it would take a supercomputer decades to crack passwords... I don't know which to believe (sorry for my ignorance on this, I'm still learning).

    I need to know what I need to do if I want to be able to keep code away from the end user, whether it be as a plug in, add in, etc.

    Below is a reference to what I found on the Internet with a Google search, however, it's dated from the early 2000's, so I'm sure there is something else out there more current and mainstream?

    http://p2p.wrox.com/excel-vba/3480-h...-vba-code.html

  2. #2
    PowerPoster
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    Oct 2010
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    Re: Excel VBA: Hiding Code from End User

    There is an old saying that goes: "locks only keep out the typically honest people".

    The password protection scheme used in Excel has been historically week, I can not comment on more recent editions. I remember a spreadsheet that I was once asked to review and update that had some sheets password protected and the person that originally wrote was on vacation. I downloaded a simple brute-force password cracker written in VBA and in 15 seconds I had a password that unlocked the sheets. It was not the actual password used to lock the sheets but it hashed to the same value as the original password and thus worked. The manager who wrote the spreadsheet was not happy as it revealed his ignorance about security (it was a design spreadsheet for "Do your own design" calc's on the corporate website for the whole world (includiing our competitors) to download and inspect.

    As there are VBA password recovery tools available, I doubt very much that anything you do short of writing the code as a COM add-in in C will do much to slow down a determined person. Even then, I am sure there people who would reverse engineer that executable in no time flat.

  3. #3
    New Member
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    Re: Excel VBA: Hiding Code from End User

    Anybody can open excel workbook with protected macros in OpenOffice, and there protection is unlocked

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