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Topic: "Guys, I could use some crypto/stegano analysis help" (page 2 of 2)

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Towley
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RE: Guys, I could use some crypto/stegano analysis help
what about bytes 260-263 ?
Germany11.06.2007 15:25:20
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Phas(retired)
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RE: Guys, I could use some crypto/stegano analysis help
It seems to be a 14 bit crc/hash/checksum at bytes 104-106 ((little endian && 0x03FFF0) >> 4):
[clear]    0000
2          0040
a1         007c
a0         01bc
aa         03fc
b          0400
c          0680
cccccccc   0e86
bbbbbccc   120f
bbbbbbcc   126f
abcdef     191a
bbbbcccc   1a0f
01234567   24a2
bbbbbbbb   30ec
bbbbbbbc   326c
ac         397d
ab         3bfd
0          3e41
1          3f81
a2         3fbd
a          3c01
ba         3c05

Extracting the function from the values is not that hard, but requires a lot of time.
I'd try with passwords like 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. Having only 3 consecutive plain texts makes it harder.
Spain11.06.2007 16:36:43
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unknown user
RE: Guys, I could use some crypto/stegano analysis help
it's under that assuption I formulated most of my hypothesis, .. there are just too many things that refuse to make sence to me :)

i'll provide the additional dumps, over time (takes a bit of effort)

tnx for looking at it.

additionally this is a diff of two dumps with no password set, across a few boots, for those convinced it are other bytes..
but then again other things might be at play here.
QuoteQuote:

1c1
< 0000000 48
---
> 0000000 22
3c3
< 0000002 02
---
> 0000002 08
5c5
< 0000004 15
---
> 0000004 00
7,8c7,8
< 0000006 02
< 0000007 11
---
> 0000006 01
> 0000007 08
55c55
< 0000066 01
---
> 0000066 80
177,180c177,180
< 0000260 02
< 0000261 32
< 0000262 33
< 0000263 a0
---
> 0000260 74
> 0000261 21
> 0000262 32
> 0000263 ac
257c257
< 0000400 48
---
> 0000400 22
259c259
< 0000402 02
---
> 0000402 08
261c261
< 0000404 15
---
> 0000404 00
263,264c263,264
< 0000406 02
< 0000407 11
---
> 0000406 01
> 0000407 08
311c311
< 0000466 01
---
> 0000466 80



the addresses are octal as usual. that prevents me from typing "-Ad" :) when invoking od,
i could also upload the raw files, if that would help anybodies analysis.
11.06.2007 16:55:33
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quangntenemy
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RE: Guys, I could use some crypto/stegano analysis help
That eliminates the other bytes :)
Now we can focus on the main part.
I suspect it's somehow similar to the other checksum algo.
Just need to work a little more with my CryptoBox :D
Vietnam12.06.2007 00:42:02
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Topic: "Guys, I could use some crypto/stegano analysis help" (page 2 of 2)

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