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n00b rainbow tables question.


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Total n00b question, don't beat me up.

So I would like to decrypt an sha1 password(yeah I know I need a supercomputer and many years)…anyway that aside, I know the salt to the hash I am trying to break and I was wondering if there was a way to build a rainbow table with the salt built in. Also if there is some other way to decrypt SHA1 that I am missing? All the forum posts I read pretty much had people just saying it wasn't possible. On wikipedia it mentions a birthday attack algorithm that may work. Anybody know anything?


ghost's Avatar
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yes man..i've heard of that kind of decryption. I myself have assembled a little program you could try.

Here's my demo. If you want the whole version..let me know.

MessageDigest oMessageDigest = MessageDigest.getInstance("SHA-1"); oMessageDigest.reset(); byte[] bPasswordInBytes = sPassword.getBytes(); oMessageDigest.update(bPasswordInBytes); byte[] bPasswordOutBytes = oMessageDigest.digest(); // encrpyted string

The only problem with the demo is decrypting it back. I could maybe give it a shot myself decrypting it too. PM me…


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Your inbox is full.


ghost's Avatar
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cain and abel is a good tool to use!


ghost's Avatar
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Don't know how but I'll give you and tip.

Don't try to get 100% tables.. (if you don't have a supercomputer) The lower your chainlength is the faster you can crack. But you got worse %. You have to balance that.

For example.

Properties:

Hash: Sha1 Min length: 1 Max length: 5 Index: 0 Chain length: 100 Chain count: 2000000 Number of tables: 1 Charset: Loweralpha-numeric

Table properties:

Keyspace: 62193780 Disk space: 30.51 MB (You can offer so much.. you can high the chain count to get the % better.) Success probability: 0.852212 (85,22%)

Benchmark (got a slow computer at moment):

Hash speed: 1065189 hash/sec Step speed: 945537 step/sec Table precomputation time: 3.52533 minutes Total percomputation time: 3.52533 minutes Max cryptoanalysis time: 0.005288 seconds (fast, faster, fastest, rt)

That's a example of the settings.

Hope this helped you and have a nice day!