Make money fast

Discussion of challenges you have already solved
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fido2509
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Joined: Thu Jul 16, 2009 8:00 pm

Make money fast

Post by fido2509 »

I don't know how the cipher works but spammimic told me the solution. ;)

Cool challenge although I still don't know how it works.


Fido
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dangermouse
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Post by dangermouse »

Probably some bits of plaintext are hidden in the numbers: e.g. Senate bill 1627 ; Title 6 , Section 303

Other bits could be hidden with different preambles, phrases or with a particular grammar:

Prof Jones who resides in Alaska with Jones=1 and Alaska=0
could be also
Prof Wes who resides in Seattle... with Wes=0 and Seattle=1

i did not do any deep analysis though.
Or am i wrong?
AMindForeverVoyaging
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Post by AMindForeverVoyaging »

Well that one went super fast.

1.) Googled for "encrypt message in spam"
2.) First hit I got is http://www.spammimic.com/
3.) Copied'n'pasted the text there
4.) Hit "decode"
5.) Done in a minute.
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Hippo
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Post by Hippo »

I have googled part of the message and got the link with hackerorg solutions :(
... OK getting to spammimic another way I would prefere more.

I have not googled the method used by spammimic, but online decoder gave the answer.
tigbits
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Post by tigbits »

Basically, the method consists of a predefined Huffman tree and a non-ambiguous context free grammar in Greibach normal form.

Take the following production:

noun -> Johnny | Drake

When parsing a text, whenever Johnny is found in place of a "noun", a 0 is noted (first choice); whenever Drake is found in place of a "noun", a 1 is noted (second choice). Thus, the spam message yields a sequence of bits that are then decoded using a Huffman tree.

Unfortunately, the grammar on SpamMimic is not disclosed.

However, for anyone interested, this is roughly how the method works.
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