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File Encryption In Excel.

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Could someone please advise me how to De- encrypt files in Excel.
I Encrypted a file some time ago, but cannot now find any item on the drop
down menu's to enable me to de-encrypt.

Thanx




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Hello:

I used to Excel 2007 at home.
Ony of my file ws encrypted by me: As PREPARE - PROPERTIES - ENCRYPT DOCUMENT. I wish to sfitch off this encryption, but couldn`t find this option.

Plese, give me advice, how to switch off encryption in Excell 2007 ?

Thanks

Ivan


Hi all,

I need to exchange encrypted, password protected Excel 2007 files with my vendor. I need to:

1. Encrypt my Excel 2007 file and send it to my vendor, and have him open the file (with the password).

2. My vendor needs to encrypt an Excel 2007 file and send it to me.

Problem is I have Excel 2007 but my vendor only has Excel 2003. Besides getting the vendor to buy 2007, is there any way around it? Also, I don't want to use Excel 2003 encryption cos I hear it's not as secure as 2007.

Thanks in advance for the advice.


I'm hoping somebody here can point me in the right direction. I work at a
small nonprofit where we manage our IT needs with the equivalent know-how of
chewing gum and duct tape.

A few weeks ago, someone in our office encrypted a few Excel spreadsheets
and folders using the right-click, Properties, Advanced. Encrypt function.
Now nobody, including that person, knows how to un-encrypt them. I've been
tasked with trying to figure it out.

Any suggestions are greatly appreciated.



Hi, I had encrypted some excel files with winzip in Vista OS. I also have a .txt file that is not encrypted in the same winzip.

Now, I have switched back to XP OS and download winzip 11.0, I am not able to extract out or view the files whether they are encrypted or non-encrypted.

The error given is

Error in file #1: bad Zip file offset (Error local header signature not found): disk #1 offset: 14744

can someone help? i appreciate your help..


Anyone know how to encrypt verbiage into an excel file (2007) that can only be removed by the author? This would be beyond the normal prepare/properties/author entry. I've been working on a project for quite some time that I'd like to have my name encrypted into without the ability for others to remove. I'd like it to print on all sheets as a very small footer. Can anyone help with this? Or is it an application add-on that I would have to get? TIA for your help.


Hi,

I had encrypted one excel file [xl2003] so it could only open transparently
when I'm logged in. It worked fine for the last year, and now suddenly it's
saying that the file is encrypted and cannot be accessed.

I tried going into properties and unchecking the 'encrypt contents to secure
data' box, but that didn't work either. I'm surprised it's not asking me for
the password.

And I tried accessing the file logged in as administrator, no luck there
again.

Any help out there?

Thanks,
Axel



I searched the archives to no avail.

Is there any sort of information on how to create an encrypted data set that can be unencrypted by an add-in? While I understand that Excel is in no way secure, I figure that forcing someone to have two files to access the data would be safer than simply trusting data to a passworded excel file/macro.

What I am thinking is as follows:
- Create an encryption algorithm for the numerical cells in a data file
- Encrypt whatever data using the algorithm
- Creating a decryption algorithm with the same algorithm as the encryption as an Add-in
- Whenever the add-in is installed, send an e-mail to me telling me that it's been installed, and relevant information (such as the computer ID and/or IP address if possible)
- On opening the encrypted file with the decryption algorithm add-in installed, it will decrypt the data, do the necessary math (coded in to the add-in), and then delete the raw data so that the leftover data can't be solved backwards to get the raw data

While I understand there would be ways around this, it would prevent a mistaken forwarded e-mail or other slip-up from handing over a chunk of crucial data, and it would give at least some rudimentary idea of how many computers the add-in is installed on.

Is there any step of this that is impossible, and is there some place that this has been done in the past to use as a base?


I have searched the forums for an answer and found none relevant for this particular problem. I need an answer from someone who has experience of the same issue.

I have an EFS encrypted Excel file. The encryption is not dependent on any password entered - it's seemless, providing instant access to the (already logged on) owner.

Suddenly, and with apparent cause, I find I cannot access the file. I've explored ALL options through permissions, control panel, etc, to set/reset/force ownership, controls, etc.

Everything indicates what's required: I own the file, I have full permissions and controls, etc. However, I can neither open the file nor remove encryption: access is denied.

I've spent considerable time seeking an answer from Microsoft forums, and many other forums found online. Scans for viruses, removal of temporary files, etc. confirm everything is well and tidy.

All routes to access the file fail: Explorer, referential access from within another spreadsheet, DOS, OpenOffice, other applications, etc.

It seems very likely there is an issue with the encryption key (damaged/lost) but the method for recreating/repairing encryption keys fails to resolve the problem. At the time of encryption, I was not aware that encryption was dependent upon a key nor that such key could be subject to possible user-backup. Microsoft don't tell you that when you click on the Encrypt button. I imagined it was seemless, self-contained, and system protected.

I've seen a Certificate Thumbprint that relates the encryption to my user-name but don't know if this humber (long hex job) is a route to a possible solution or not.

I have yet to find any solution to my problem. Any intelligent, knowledgeable ideas?

The set-up is MS Office 2003 and XP Professional.

Thanks in anticipation.


I've done a little bit of searching but am hoping someone on here can help me out more quickly. I have a client that is using Excel 2000, we're using Excel 2003. They have an excel file that needs to be encrypted & sent back to us. I sent instructions on how to encrypt, but apparently it's not the same for 2000. Can anyone give me step by step encryption instructions for 2000? This client has some knowledge of computers, but instructions would need to be pretty basic since I'll be reading them off & can't see what he's seeing.


Hi all

I've been making enquiries on the Excel board (http://www.mrexcel.com/forum/showthread.php?t=550524) regarding running queries from Excel on a database with password protection.

I've got that bit sorted but now I need to know about database encryption.

If you look at post #13, I've come a bit unstuck.
Because of what the database contains, I need to encrypt it. That gives me 3 questions:-

1) What's the best way of encrypting the database to keep the information at least reasonably secure?
2) Will my code on the other thread still work with an encrypted database?
3) If it won't, how would I modify it so that it does?

There is an option in Tools/Security to Encode/Decode the database but it would appear I need Workgroup administration for that.

Can someone please explain the best way to encrypt the database while still allowing Excel to run the queries and return the data?

All help greatly appreciated.


I have a macro that will send a screenshot, everything works perfectly the only thing I want it to do that it doesn't do it encrypt my email.. the setting is found in outlook under File/Properites - security tab and first check box to "Encrypt message contents and attachments"... is the a trigger I can use that would activate this??


I want to encrypt text in Excel. I want the character spacing to be accurate,
I just want the actual text to be encrypted to a user. Anyone know any
tricks, shortcuts, add-ins to do this?
Thank you!

Marc



Had a workbook with macros developed in Excel 97. Loaded it into excel 2007. Works fine saved it in xlsm format. If I try to encrypt the file I get error message that basically says can't do it with old macros. I cannot find any reference on how to change macro sto be Excel2007 compatible. Is there one? So I saved the file in xls format. All is OK.

BUT, if I converted or rewrote the macros, I have read about another problem (and duplicated it). apparently you cannot open encrypted xlsm files with macros enabled. Can't find a way to override this. Found some reference to SP2. Thats what I have running. Found suggestions for registry change to disable virus scan of macros. Did not work.


Hi

Does anyone know what the VBA code is to encrypt a document (or even just bring up the encrypt dialogue box). Basically, I just want to programmatically password protect a workbook before it's automatically emailed and it's driving me crazy!

Any help would be appreciated

Cheers

Dave


Hi,

I understand how to password protect an excel file, how do I encrypt a folder with excel files, so no one can get in the folder. Are there free software somewhere>?

I have windows XP and Excel 2002

Thanks


I've done a little bit of searching but am hoping someone on here can help me out more quickly. I have a client that is using Excel 2000, we're using Excel 2003. They have an excel file that needs to be encrypted & sent back to us. I sent instructions on how to encrypt, but apparently it's not the same for 2000. Can anyone give me step by step encryption instructions for 2000? This client has some knowledge of computers, but instructions would need to be pretty basic since I'll be reading them off & can't see what he's seeing.


Hello everyone
Was wondering if someone could help me.
I have some data calculations on excel (using solver for iterations)
and would like to get it encrypted for protection via HASP keys. The
only two mode to do this is via encrypting .exe files or from VBA
itself - linked to the key via DLL.
Firstly, is there any way I could convert my EXCEL file (with macros)
into .exe (without getting ALL other excel files encrypted as well and
not infringing with Microsoft's EULA)?

Secondly, how do I get my excel file to communicate to the HASP key via
VBA?

Many thanks in advance for your help
Faz




A long while ago in Excel 2003, I created a spreadsheet that has macros. Our company converted to 2007 and turned off the ability to keep macros enabled. We can enable them each time we load the spreadsheet, so that's OK I guess.

We have one spreadsheet that won't allow the user to enable macros. When loaded and they click on options to enable the macros, that option isn't there. Instead they receive the following message:

Security alert.
This file contains encrypted macros that have been disabled because there is not anti virus software installed that can scan them. To run these macros, remove the encryption or permission restrictions on the file.

I search here and found out about the Save As --> tools --> general options, there is no password in there.

Any ideas out there.
Thanks
Mark


Snipped from Bruce Schneier's monthly CRYPTO-GRAM

"Microsoft RC4 Flaw

One of the most important rules of stream ciphers is to never use the
same keystream to encrypt two different documents. If someone does, you
can break the encryption by XORing the two ciphertext streams together.
The keystream drops out, and you end up with plaintext XORed with
plaintext -- and you can easily recover the two plaintexts using letter
frequency analysis and other basic techniques.

It's an amateur crypto mistake. The easy way to prevent this attack is
to use a unique initialization vector (IV) in addition to the key
whenever you encrypt a document.

Microsoft uses the RC4 stream cipher in both Word and Excel. And they
make this mistake. According to a paper by Hongjun Wu: "In this
report, we point out a serious security flaw in Microsoft Word and
Excel. The stream cipher RC4 [9] with key length up to 128 bits is used
in Microsoft Word and Excel to protect the documents. But when an
encrypted document gets modified and saved, the initialization vector
remains the same and thus the same keystream generated from RC4 is
applied to encrypt the different versions of that document. The
consequence is disastrous since a lot of information of the document
could be recovered easily."

This isn't new. Microsoft made the same mistake in 1999 with RC4 in
WinNT Syskey. Five years later, Microsoft has the same flaw in other
products.

The report (PDF):
<http://eprint.iacr.org/2005/007.pdf>"

The pdf file is interesting. Any comments?

/Fredrik





Hi,
I have created a Password which should be typed onto a Input box provided by VB to Open a Remote File.
The text is Visible.
Pl help me by providing tips as to Encrypt the String....

Regards,

Vijay Anand.R




Hi,

I'm creating a addin for my company to remind users to encrypt their workbooks if they need to.
Currently I have it working however, I'm looking to prevent this still showing after they have protected their work.

We protect our files by clicking file -> protect workbook -> encrypt with password.

Is there anyway to check that the workbook is already protected with this method?

If yes how?

Many thanks

I have encyrpted my .accdb with a password using ACCESS 07's Encrypt with Password feature. I want users to be able to change this password, so can anyone come up with VBA code to call on the Encrypt with Password dialogue?


Does anyone know of a way to further secure excel worksheets/workbooks? It kind of defeats the purpose to protect a sheet when someone who knows a little more than nothing can get on the net and paste in the VBA to unprotect a sheet. Just curious if anyone else had any ways of protecting their data.

Note: The workbook is a template people need to use so I can't encrypt the whole file.


Hi Guys,

I'm looking for a software or a way to encrypt Excel worksheet so that the recipient of the file can't download a password recovery software and can unprotect the worksheet. Excel worksheet protection is not that good.


I have an issue with multiple workbooks, with multiple spreadsheets that have columns that include credit card data that I would like to encrypt via a macro. I cannot use the spreadsheet password encryption as many people need to access the spreadsheet and be able to reference the last 4 digits of the cc. The cc info is in more than one worksheet so I would like to build a macro that searches the work book for a cell that contains 15 or 16 characters and encrypts or deletes all but the last 4 digits and save this to personal project to use on many workbooks. Does anyone know if this is possible?

Greatly appreciated!

Cheers,
hb