Damaged/Lost Encryption Key

DaveSmiler

New Member
Joined
Feb 26, 2011
Messages
2
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 <!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:PunctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w:DontGrowAutofit/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> </w:WordDocument> </xml><![endif]--><!--[if gte mso 9]><xml> <w:LatentStyles DefLockedState="false" LatentStyleCount="156"> </w:LatentStyles> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} </style> <![endif]-->MS Office 2003 and XP Professional.

Thanks in anticipation.
 
Last edited:

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xenou

MrExcel MVP
Joined
Mar 2, 2007
Messages
16,836
Office Version
  1. 2019
Platform
  1. Windows
This article protecting efs encryption suggests you can log in as Administrator (not any adminstrator (?) but the administrative user named Administrator) and fix the problem:

The local Administrator account (the Administrator account, not someone from the Administrators group) is automatically a recovery agent for the machine. If a user locks themselves out of an encrypted file, the Administrator can log in, take ownership of the file, grant themselves access to the file, and then remove the encryption bit or use the Cipher command to decrypt the file.
 

DaveSmiler

New Member
Joined
Feb 26, 2011
Messages
2
Thanks for trying to help.

Even logged in as administrator with evident file ownership, full controls and all permissions, I cannot access the file or switch off encryption.

Cipher seems geared towards directories rather than files. Running it (/d) - even from different points in the file structure to target the file, it's directory, etc. - had no effect. If there exist clear insturctions on how to use cipher explicitly for a file then I'd be interested. However, all command prompt feedback I get refers to "Decrypting directories" and none of my attempts have altered the status of the file.

I can see the encryption details associating my account with the "Certificate Thumbprint" (long hex number) which seems like it is well but I dont know if that's a clue to an new avenue towards a solution.

Certainly, I have very thoroughly explored very many alternate routes of ownerships, button-clicks, etc.
 

xenou

MrExcel MVP
Joined
Mar 2, 2007
Messages
16,836
Office Version
  1. 2019
Platform
  1. Windows
I doubt I'll get any further than you but if I find any more information that sounds useful I'll pass it along. You may need to seek the help of an expert in file recovery. Any idea how this happened? Did anything strange happen with your login password?

I'm a fan of TrueCrypt, by the way, if after this you decide you're looking for an alternative to EFS for encryption.
 
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