Cross-platform password-cracking Ophcrack to break the speed is incredible. In the end how fast? It can break 160 seconds "Fgpyyih804423" the password. Many people think that the password is quite safe. Microsoft's password strength tools to determine that the password security level is "strong." Geekwisdom and password Estimator strength of the password that Intensity is the safety of "ordinary."
Ophcrack to break the speed of why so fast? This is because it used the rainbow table. I said I was not used as a desktop background that the real rainbow.
However, the rainbow is also a beautiful table.
Rainbow table in order to understand the working principle, first of all you have to understand is how to store computer passwords, whether in your own desktop or used in remote network server where.
ĄŁ No password is stored in plain text of the document. At least we should not do, unless you use one of the world's most naive of the process, and your goal is to build the world's most insecure system. In fact, we should as a password hash function to store the output value. Hash is a one-way operation. Even if an attacker to read the password hash table, he can not only through the password hash table to reconstruction.
However, an attacker could use to attack the Rainbow Hashtable password hash table: a huge, for every possible combination of letters in advance the good hash value. The attacker, of course, the computer can also run in the calculation of the value of all, but the use of pre-calculated value of a good hash of a large table, obviously could allow an attacker to be able to more quickly implement the order of the size series - the assumption that there are enough machines to attack The large RAM to store the entire table into memory (or at least most of the table). This is very typical of the time - memory trade-offs, in particular, the hackers tend to use this shortcut.
How does a huge rainbow table? Ophcrack the installation of a dialogue, then you have a general concept:
These generate huge rainbow table takes a long time, but once the generation of good, then attacked each computer can be used to crack the table stronger password hash table.
Rainbow smallest available table is the most basic alphanumeric list, so it will have the size of 388MB. Even the smallest of the table is quite effective. I use it to attack my Windows XP in a virtual machine on the set of passwords, the results are as follows:
found? seconds found? seconds
Password1! 700 Password1! 700
Fgpyyih804423 yes 159 Fgpyyih804423 yes 159
Fgpyyih80442% 700 Fgpyyih80442% 700
saMejus9 yes 140 saMejus9 yes 140
thequickbrownfoxjumpsoverthelazydog 700 thequickbrownfoxjumpsoverthelazydog 700
Of course, you can not solve this kind of rainbow table with a number of non-letter characters in the password (such as %&^$# this), because there is no table contains these characters. You may have also noticed that the passphrase, I also like them because of the length of their own problems, passphrase for this technology is immune.
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