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> ...but the most complex... Those would be the passwords that we're talking about here. Next time you run either, take a look at the count of uncracked passwo

> ...but the most complex... Those would be the passwords that we're talking about here. Next time you run either, take a look at the count of uncracked passwords. There are always some, which should tell you something. Also, I couldn't reply to you before so see my reply to parent WRT rainbow table size. They're not the panacea you're implying.

Alupis 11y ago
> They're not the panacea you're implying. But they are - we have a hard-limited keyspace, with a fixed well-known and understood algorithm, which means, regardless of disk size, a rainbow table can (and has been) generated to cover the entire LM/NTLM space. This place just has a few for starters[1] [1] http://project-rainbowcrack.com/table.htm http://project-rainbowcrack.com/table.htm
- dsp1234 11y ago
  (and has been) generated to cover the entire LM/NTLM space I don't think this is true. Certainly true for the LM space of 7 characters, but the size of the NTML rainbow table for all passwords of length 1-9 with "only" mixed alphanumeric is 690GB with a key space of 13,759,005,997,841,642. This doesn't include the fact that a windows password can use any unicode character. So while there is could be some sort of collision with a shorter password, it's not really likely. Note that windows passwords can be up to 127 unicode characters, but that in win2k/2k3 the actual dialog box would only allow 32. So we're talking quite a bit more space to have each combination stored. Additionally, unless I'm doing some bad math here, it's just not currently possible to have a rainbow table that includes all possible MD4 hash values. An MD4 hash is 16 bytes, which is 128 bits. In order to just list each hash would take 16 bytes * 2^128 = 5 * 10^39 bytes, which is something like 5 * 10^27 terabytes, 5 * 10^13 yottabytes, etc. This doesn't include any space to list whatever password caused that hash to be calculated. And directly 'reversing' an MD4/NTLM hash still requires a preimage attack on MD4 and the current best known is still at a complexity of 2^121 [0], which would likely still be more feasible than having access to an MD4 rainbow table with all possible hash values. [0] - https://who.rocq.inria.fr/Gaetan.Leurent/files/MD4_FSE08.pdf https://who.rocq.inria.fr/Gaetan.Leurent/files/MD4_FSE08.pdf
- Godel_unicode 11y ago
  The limited key-space is the full set of unicode characters which have alt-codes and can thus be typed into a password prompt. This is a much larger key-space than the traditional a-zA-Z1-9 space most people use in their tables. Anecdotally (insert usual HN isn't real life quote) I polled the people I work with and roughly 1/3 of us paranoiacs have at least one such character. What you're saying is akin to saying you can defeat AES by generating all possible keys and trying them. Possible? Totally. Realistic? No. You have repeatedly now said that such a table exists. Source? How big was it, and at what work factor was it created? Keep in mind that the full space is all alt-codes and must cover passwords up to length 127. The site we have now both linked to does not have such a table.

Alupis 11y ago

> They're not the panacea you're implying. But they are - we have a hard-limited keyspace, with a fixed well-known and understood algorithm, which means, regardless of disk size, a rainbow table can (and has been) generated to cover the entire LM/NTLM space. This place just has a few for starters[1] [1] http://project-rainbowcrack.com/table.htm http://project-rainbowcrack.com/table.htm

dsp1234 11y ago
(and has been) generated to cover the entire LM/NTLM space I don't think this is true. Certainly true for the LM space of 7 characters, but the size of the NTML rainbow table for all passwords of length 1-9 with "only" mixed alphanumeric is 690GB with a key space of 13,759,005,997,841,642. This doesn't include the fact that a windows password can use any unicode character. So while there is could be some sort of collision with a shorter password, it's not really likely. Note that windows passwords can be up to 127 unicode characters, but that in win2k/2k3 the actual dialog box would only allow 32. So we're talking quite a bit more space to have each combination stored. Additionally, unless I'm doing some bad math here, it's just not currently possible to have a rainbow table that includes all possible MD4 hash values. An MD4 hash is 16 bytes, which is 128 bits. In order to just list each hash would take 16 bytes * 2^128 = 5 * 10^39 bytes, which is something like 5 * 10^27 terabytes, 5 * 10^13 yottabytes, etc. This doesn't include any space to list whatever password caused that hash to be calculated. And directly 'reversing' an MD4/NTLM hash still requires a preimage attack on MD4 and the current best known is still at a complexity of 2^121 [0], which would likely still be more feasible than having access to an MD4 rainbow table with all possible hash values. [0] - https://who.rocq.inria.fr/Gaetan.Leurent/files/MD4_FSE08.pdf https://who.rocq.inria.fr/Gaetan.Leurent/files/MD4_FSE08.pdf
Godel_unicode 11y ago
The limited key-space is the full set of unicode characters which have alt-codes and can thus be typed into a password prompt. This is a much larger key-space than the traditional a-zA-Z1-9 space most people use in their tables. Anecdotally (insert usual HN isn't real life quote) I polled the people I work with and roughly 1/3 of us paranoiacs have at least one such character. What you're saying is akin to saying you can defeat AES by generating all possible keys and trying them. Possible? Totally. Realistic? No. You have repeatedly now said that such a table exists. Source? How big was it, and at what work factor was it created? Keep in mind that the full space is all alt-codes and must cover passwords up to length 127. The site we have now both linked to does not have such a table.