5 ms·
>However, any possible password with a standard printable ASCII character set will typically be found in Rainbow tables up to 10 characters long making expensiv
by forgotpwtomain 9y ago
>However, any possible password with a standard printable ASCII character set will typically be found in Rainbow tables up to 10 characters long making expensive cracking unnecessary.
Umm what? Even assuming a limited set of ASCII i.e. Base64, on what magical medium do you suppose a 64^10 rainbow table is stored?
- morecoffee 9y agoAny medium really. Rainbow tables are compressed (by throwing away most of the hashes). The amount you throw away determines how long it takes to crack. For example, A rainbow table might use chain lengths of 10,000. This means that for every 10,000 hashes calculated, only 1 (really 2) are kept. Each chain ends up as a row in the table, which is then sorted. When cracking, the target hash is hashed and reversed up to 10,000 times looking through the table. The more compression the less space needed, but longer look up. The original Windows XP rainbow table cracking CD published along with the Rainbow table paper was only ~500Mb, but was able to crack pretty much every windows password.
- Godel_unicode 9y agoAn md5 rainbow table for lower alphanumeric which covers passwords of length 9 is 63gb. Length 10 is 316gb. You can see where this is going. It's important to note the caveat upfront; lower case-only plus numbers. No upper case, no symbols. http://project-rainbowcrack.com/table.htm http://project-rainbowcrack.com/table.htm
- morecoffee 9y agoThat is just a rainbow table, but there are many others. By modifying the chain length, you can make the table as arbitrarily small. The example commands on that site use a chain length of 3800, but it could be raised to 1 million.