Re: Using Spark to crack passwords

2014-06-12 Thread Sean Owen
You need a use case where a lot of computation is applied to a little data. How about any of the various distributed computing projects out there? Although the SETI@home use case seems like a cool example, I doubt you want to reimplement its client. It might be far simpler to reimplement a search

Re: Using Spark to crack passwords

2014-06-12 Thread Nicholas Chammas
Indeed, rainbow tables are helpful for working on unsalted hashes. They turn a large amount of computational work into a bit of computational work and a bit of lookup work. The rainbow tables could easily be captured as RDDs. I guess I derailed my own discussion by focusing on password cracking, s

Re: Using Spark to crack passwords

2014-06-12 Thread Marek Wiewiorka
This actually what I've already mentioned - with rainbow tables kept in memory it could be really fast! Marek 2014-06-12 9:25 GMT+02:00 Michael Cutler : > Hi Nick, > > The great thing about any *unsalted* hashes is you can precompute them > ahead of time, then it is just a lookup to find the p

Re: Using Spark to crack passwords

2014-06-12 Thread Michael Cutler
Hi Nick, The great thing about any *unsalted* hashes is you can precompute them ahead of time, then it is just a lookup to find the password which matches the hash in seconds -- always makes for a more exciting demo than "come back in a few hours". It is a no-brainer to write a generator function

Re: Using Spark to crack passwords

2014-06-11 Thread Akhil Das
You can have a huge dictionary of hashes in one RDD and use a map function to generate a hash for the given password and lookup in your dictionary RDD. Not sure about the performance though. Would be nice to see if you design it. Thanks Best Regards On Thu, Jun 12, 2014 at 7:23 AM, Nicholas Cham

Re: Using Spark to crack passwords

2014-06-11 Thread Nicholas Chammas
Yes, I mean the RDD would just have elements to define partitions or ranges within the search space, not have actual hashes. It's really just a using the RDD as a control structure, rather than a real data set. As you noted, we don't need to store any hashes. We just need to check them as they are

Re: Using Spark to crack passwords

2014-06-11 Thread Marek Wiewiorka
What about rainbow tables? http://en.wikipedia.org/wiki/Rainbow_table M. 2014-06-12 2:41 GMT+02:00 DB Tsai : > I think creating the samples in the search space within RDD will be > too expensive, and the amount of data will probably be larger than any > cluster. > > However, you could create a

Re: Using Spark to crack passwords

2014-06-11 Thread DB Tsai
I think creating the samples in the search space within RDD will be too expensive, and the amount of data will probably be larger than any cluster. However, you could create a RDD of searching ranges, and each range will be searched by one map operation. As a result, in this design, the # of row i