It’s all crackable!

I smile every time I hear of “the laptop is safe as it is encrypted”, or that “the password has hashed, so it was okay”. Unfortunately neither of these methods are safe, and we have managed to crack every encrypted laptop we have been given, and cracked many hashed password (of normal user accounts).

The flaw for encrypted content

The key flaw of encrypted content is not the encryption method or the key used, it the way that the encryption key is used. For most purposes the key is stored under the control of the password, either directly when the user it prompted, or where it protects a digital certificate. For an encryption key with 115,792,089,237,316,195,423,570,985,008,687, 907,853,269,984,665,640,564,039,457,584,007,913,129,639,936 different keys actually is reduce to something that can normally be found in a standard dictionary (with a few additional characters, of course), which is around 200,000 is length. This makes it fairly easy for a brute force on the protected encryption key. In the following I crack AES:

http://buchananweb.co.uk/adv_security_and_network_forensics/dotnetclient_brute/dotnetclient_brute.htm

and here I crack a digital certificate:

http://buchananweb.co.uk/adv_security_and_network_forensics/dotnetclient_digitalcert/dotnetclient_digitalcert.htm

When faced with creating a password for your encrypted content, we are unlikely to choose a complex one, thus most of the time users pick simple ones, which actually have a weaker strength than most login passwords.

The flaw of hashes

A hash signature is meant to be an irreversible code, but they can be easily overcome using a rainbow table, where we create hash values for a range of well-known phases. So let’s try a few countries, the capital city, and the language spoken. First we will try Germany:

http://www.asecuritysite.com/Encryption/md5?word=Germany

which gives an MD5 signature of D8B00929DEC65D422303256336ADA04F

Next we will crack it:

http://www.asecuritysite.com/Encryption/md5c?word=D8B00929DEC65D422303256336ADA04F

which gives us a cracked value of “Germany”. So for “Berlin”:

http://www.asecuritysite.com/Encryption/md5?word=Berlin

which gives an MD5 signature of EE1611B61F5688E70C12B40684DBB395

Next we will crack it:

http://www.asecuritysite.com/Encryption/md5c?word=EE1611B61F5688E70C12B40684DBB395

and final we code “German”, to give:

http://www.asecuritysite.com/Encryption/md5?word=German

which gives an MD5 signature of 86BC3115EB4E9873AC96904A4A68E19E

Next we will crack it:

http://www.asecuritysite.com/Encryption/md5c?word=86BC3115EB4E9873AC96904A4A68E19E

and we see that it cracks it. So we have manged to crack all of these.

Conclusion

So, unfortunately, you really need to understand your encrypted content, and how the key is stored to properly know if your data is secure.

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