11-29-2010, 12:09 PM
1. multihash means that you have the ability to crack multiple (unsalted) hashes at once without loosing speed (just a bit). so it doesnt matter if you crack 100 md5 hash or 1000, the speed remains the same. this is done using some special bitmap table that are dynamically generated on startup. however this works only on unsalted hashes.
2. yeah its not optimized on brute-force but of course you can do it. oclHashcat is optimized to crack with combinator or in hybrid attack. however rule-based cracking as in jtr is not targeted by oclHashcat. for example check out the fingerprint attack: http://www.question-defense.com/2010/08/...int-attack
3. yes. the absolute max is 16 gpus. but there are more, mostly caused by unfixed bugs in the opencl implementation of the vendors or by driver limits. for example, gpgpu using opencl on ati is limited to 4 gpus by the driver. you should also have at least that number of cpu cores equal to the number of gpus.
4. get good wordlists like the rockyou.txt and check out batchcrack.sh
2. yeah its not optimized on brute-force but of course you can do it. oclHashcat is optimized to crack with combinator or in hybrid attack. however rule-based cracking as in jtr is not targeted by oclHashcat. for example check out the fingerprint attack: http://www.question-defense.com/2010/08/...int-attack
3. yes. the absolute max is 16 gpus. but there are more, mostly caused by unfixed bugs in the opencl implementation of the vendors or by driver limits. for example, gpgpu using opencl on ati is limited to 4 gpus by the driver. you should also have at least that number of cpu cores equal to the number of gpus.
4. get good wordlists like the rockyou.txt and check out batchcrack.sh