[ LastBit Software Home Page ] [ Help Index ]
Word and Excel implement quite similar protection systems so we prepared the combined documentation for both. The used protection system is quite complex with lots of nuances, depending on the MS Office version, so, please, read this instruction carefully.
In both Word and Excel there are several types of passwords that are differently implemented, moreover in different versions of MS Office the password protection is implemented differently, thus causing additional confusion.
We prepared the following schemes that show different types of passwords and possible variants of password recovery: Excel Recovery Scheme and Word Recovery Scheme.
In short: all passwords except passwords to open are weak and can be cracked instantly no matter how long and complex the password is.
In case of Password to open there are three variants of protection: Weak protection, Office 97/2000 compatible protection and Advanced Encryption. In old Office versions (through Office 95) only Weak protection was used. In Office 97 and 2000 only "Office 97/2000 compatible protection" is used. In new Office versions beginning with XP all three variants are supported and the default variant is "Office 97/2000 compatible protection". Most documents are protected using this protection mode. The French version of Office always uses Weak protection (as the French laws limit the strength of encryption software).
If the document is encrypted in the Weak protection mode, the password can be recovered instantly regardless of its length. However, there can be problems if the document contains too little text. In this case we can recover the document manually, please contact us for more details.
If the document is protected in the Office 97/2000 compatible protection mode, there are two variants of password recovery. First, Universal Recovery Methods can be used, such as brute force attack (exhaustive search) or Dictionary Attack (linear search). The manual on using Universal Recovery Methods can be found here. These methods perform quickly and efficiently if the password is short and/or simple. The longer the password is, the more time is needed to recover it. Long passwords can require too much time and efforts. You can estimate the required recovery time using Password Calculator. Most competitive programs use only this method. This means that a real document protected with a long password cannot be recovered by such a program.
Another way is to use Guaranteed or Express Recovery. Guaranteed Recovery, developed by our company in 1999 guarantees that a password protected document will be recovered regardless of the password length. In recent years, we improved this technology to a high degree of perfection and new Express Recovery recovers any document regardless of the password length in just a minute! However, there is a number of caveats, the most important ones are the following:
- The password remains unknown. If you have several documents to recover, each of them must be recovered individually; see this article for more information.
- The recovery process is actually performed in our data center and requires a significant amount of resources. That's why we have to impose a per document recovery fee. Word Password and Excel Password include one recovery voucher, this means that if you bought Word Password or Excel Password you can recover one document.
- Guaranteed/Express Recovery was developed with privacy concerns in mind; you don't have to send your document to, our software extracts a small fragment (about 50 bytes) from the document header, it contains no information about the content of the document. Then in our data center, using this fragment we will find the encryption key your document was encrypted with and send this key to you. Then, the program will decrypt your document. The encryption is performed on your computer, the contents of the document does not leave your computer. This is performed automatically in a minute that the recovery process takes.
- Express Recovery has some additional limitations. It can be temporary unavailable, besides, about 5% of Excel documents cannot be recovered using Express Recovery (but they still can be recovered using Guaranteed Recovery). In case Express Recovery is impossible or unavailable, we recommend you to use Guaranteed Recovery. We guarantee and give you a money back guarantee that your document will be recovered in 36 hours (usually, this time is much less).
- Find more information here - please, read this.
The new versions of Word Password and Excel Password allow you to perform Post Guaranteed Recovery - search for the original password after the document is recovered using Guaranteed or Express Recovery. The search is performed significantly (2+ times) faster than usual.
If the document is encrypted in the Advanced Encryption mode, then, unfortunately, Guaranteed/Express Recovery will not be able to recover it. You will have to use Universal Recovery methods.
How can I find out the mode the document was protected in?
It is very easy, just launch Word Password or Excel Password (demo version is ok), click "Open" and select the document. If the document is protected in the Weak protection mode, you will receive the password immediately, otherwise the select recovery mode dialog will appear. At the top of the window you will see information about the document, including its encryption mode. Besides, if the document was protected in the Advanced Encryption mode, the Guaranteed/Express Recovery option will be disabled.
Other password types
If the Word document is protected with a password to modify or document protection password, Word Password will use the "Reset the Password" recovery method, i.e. it will modify the document to remove the password. The original password will remain unknown.
If the Excel workbook is protected with a password to modify or workbook/worksheet protection password, the "Fake Password Creation" recovery method will be used. The constructed "fake" password will be accepted as a valid one.
Special note on VBA passwords.
Word Password and Excel Password do not allow recovering passwords for VBA modules, integrated into Word or Excel documents. We developed the special VBA Password program for this purpose. If the document has a password-protected VBA module and, besides this, the document is protected with a password to open, you must first use Word Password or Excel Password to remove the password to open and then use VBA Password to recover the VBA module password.
If the Word or Excel document is damaged, it may be impossible to recover the password.
Sometimes, instead of using standard means if protection, password protection can be implemented using macros in the included VBA module. Such protection presents no difficulties and can be easily removed, but it has to be done manually.
Document preview feature (for Word 97/2000/XP/2003 documents
Word Password can show you a part of your password-protected document even if the password is unknown. You will see the beginning of your document. The displayed part of the document will be somewhat garbled (probably significantly).
Optional Technical Information On Password Protection in Word and Excel
New versions of Word and Excel use the RC4 encryption algorithm and hash passwords using the MD5 algorithm. Due to the export restrictions on cryptographic software that existed until recently, the length of the encryption key was limited by 40 bits. This means that we have about a trillion variants: 1,099,511,627,776. When you use Guaranteed Recovery, we check each of these 1,099,511,627,776 variants in our data center and find the one that your document was encrypted with. The decryption process is performed on your computer, and the content of the document is not transmitted over the network. Express Recovery is a further development of Guaranteed Recovery. In this technology we have built a multiterabyte table that allows us to drastically reduce the search time. As with Guaranteed Recovery, the decryption process is performed on your computer and the content of the document is not transmitted over the network.
The recovery methods used by Word Password and Excel Password (click to find more information on each method):
[ LastBit Software Home Page ] [ Help Index ]