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roger_grimes
Columnist

Phillip Oechslin responds to my Rainbow Table column

Analysis
Jan 18, 20072 mins
Data and Information SecuritySecurity

Rainbow Method and Table creator Phillip Oechslin emailed me regarding my recent column on Rainbow tables. Here's his email. Hello Roger, I just saw your online article on CSO online in Australia. I thought you might interested to know that rainbow tables can also be used to crack office documents. The default encryption scheme of Word and Excel has the same default as Windows password hashes, it is predictible

Rainbow Method and Table creator Phillip Oechslin emailed me regarding my recent column on Rainbow tables.

Here’s his email.

Hello Roger,

I just saw your online article on CSO online in Australia.

I thought you might interested to know that rainbow tables can also be used to crack office documents. The default encryption scheme of Word and Excel has the same default as Windows password hashes, it is predictible (there is no salt or randomness).

We have a product that cracks a Word or Excel document in minutes, whatever the password (any length or complexity, since what we crack is not the password but the resulting 40 bit key that is used to encrypt the document).

I could get you a evaluation version if you wanted to test (would have to send you a DVD with the 4GB of tables). Alternatively I could crack a few documents for you.

There is info on this on our product page:

https://www.objectif-securite.ch/en/products.php

Well and you write: “Rainbow tables are closely related to a cracking technique pioneered by Philippe Oechslin”.

Actually rainbow tables have been invented by Philippe Oechslin. I should know. I coined the name rainbow table in my research paper presented at Crypto 2003.

https://lasecwww.epfl.ch/pub/lasec/doc/Oech03.pdf

BTW, we have a large article in the February issue of Hackin9

(https://en.hakin9.org/) magazine about rainbow tables and how we optimize their implementation.

regards,

Philippe

roger_grimes
Columnist

Roger A. Grimes is a contributing editor. Roger holds more than 40 computer certifications and has authored ten books on computer security. He has been fighting malware and malicious hackers since 1987, beginning with disassembling early DOS viruses. He specializes in protecting host computers from hackers and malware, and consults to companies from the Fortune 100 to small businesses. A frequent industry speaker and educator, Roger currently works for KnowBe4 as the Data-Driven Defense Evangelist and is the author of Cryptography Apocalypse.

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