/prog/ - Cryptography [PART I]

Name: Cryptography 2012-10-16 22:36

Cryptography

Name: exploiting ignorance 2012-10-16 22:42

exploiting ignorance

Name: Anonymous 2012-10-16 22:48

Name: Anonymous 2012-10-16 22:53

>>3
Kikes are pretty smart. What about it?

Name: Anonymous 2012-10-16 22:54

I was thinking about a very simple steganographic technique to simulate the noise floor for lossless image formats. It assumes that the input bitstream is already encrypted and has uniform distribution. The algorithm is as follows: Divide the image into 2x2 pixel blocks. Consider the MSB of each pixel in a block. If it's not ((1,0),(0,1)) or ((0,1),(1,0)), then skip to the next block. Take a bit from the input; if it is 0, replace the block's pixels' MSBs with ((1,0),(0,1)); otherwise, replace them with ((0,1),(1,0)). Repeat the process until you run out of input bits. The main disadvantage of this technique is, of course, that the vessel data needs to be 32 times larger than the signal. But at least it should be very hard to detect.

>>2
I don't get it.

Name: Anonymous 2012-10-16 22:55

>>3 proves that VIPPER was actually right all along; FFP and the jew spammer are the same person.

Name: Anonymous 2012-10-16 22:56

Why does >>3 prove that, >>6-kun?

Name: Anonymous 2012-10-16 23:02

>>7
Although they ``both'' post within the same hours, they never post at the same time. And now that FFP found a new way to enrage neckbeards (by spitting on cryptography), the jew spammer decided to do the same. Could be just coincidence, of course.

Name: Anonymous 2012-10-16 23:04

>>8
Oh, okay.

Name: Anonymous 2012-10-16 23:05

>>8
they never post at the same time
I have yet to see two people posting at the same time in this board.

Name: Anonymous 2012-10-16 23:33

>>10
http://dis.4chan.org/read/prog/1350278658/136
http://dis.4chan.org/read/prog/1350406528/22

Name: Anonymous 2012-10-16 23:41

>>11



vim ~/.mozilla/firefox/profiles/.../HTTPSEverywhereRules/world4ch.xml



<ruleset name="World4ch">

  <target host="dis.4chan.org" />



  <rule from="^http://(dis\.)?4chan\.org/" to="https://dis.4chan.org/"/>

</ruleset>

Name: Anonymous 2012-10-16 23:51

>>12
vim
Strike 1.
firefox
Strike 2.
xml
Strike 3. Stopped reading.

Name: Anonymous 2012-10-17 3:22

>>10
I see several people posting concurrently on this board pretty damn often.

Name: Anonymous 2012-10-17 9:56

>>5
Interesting; have you tested your technique against steganalysis tools?

Name: Anonymous 2012-10-17 10:07

>>11
hey i posted both of those

Name: Anonymous 2012-10-17 11:31

>>15
I have not tested my anal techniques against a stegosaurus. Why have you asked?

Name: Anonymous 2012-10-18 1:09

>>5
I wonder if this would work for audio. On a related note, I wonder how I can get some proper vessel files; I suppose I could just record myself playing the piano and save the file as uncompressed 32-bit FLAC.

Name: Anonymous 2012-10-18 2:30

>>18
If you're going to use steganography, perhaps broadcasting the format and contents of your vessel files on the Internet is not such a great idea.

Name: Anonymous 2012-10-18 11:40

>>19
uncompressed 32-bit FLAC
holy jesus

Name: Anonymous 2012-10-18 12:46

>>20
Nothing's stopping him from compressing the audio after recording

Name: Anonymous 2012-10-18 12:48

>>20
Fine, losslessly-compressed audio. Happy now, Captain Autism?

Name: Captain Autism 2012-10-18 12:56

I am quite happy without having to listen to your shit!

Name: Anonymous 2012-10-18 13:17

>>21
Lossily-compressing audio most likely destroys all steganographically-hidden data in it.

Name: Anonymous 2012-10-18 13:26

>>24
Not if you wrote it the right way.

Name: Anonymous 2012-10-18 13:31

>>24
If you're going to need that sort of requirement, it'd also be your responsibility to write a compliant encoder. Since the FLAC encoder is free, it'd be relatively trivial to do this with FLAC.

Name: Anonymous 2012-10-18 13:36

>>26
FLAC is lossless. This means that no matter what input stream you encode with it, when you decode it you get back the exact same thing bit-for-bit (they even store a MD5 checksum of the uncompressed stream).

On another note, I don't know how you're going to get enough entropy to cover 32 bits of PCM out of a regular DAC that has probably 12 or 14 bits of resolution. I would suggest sticking to 8 bits.

Name: Anonymous 2012-10-18 16:02

>>27
Cryptography thread
FLAC
...
imouttahere.png

Name: Anonymous 2012-10-18 17:47

>>28
/le backseat bop/

Name: Anonymous 2012-10-18 18:10

>>28
fuck off, retard

Name: Anonymous 2012-10-20 2:08

>>2
What do you mean?

>>1
Here's an interesting problem; is it possible to do public key steganography (i.e. with no shared secret)?

Name: >>31 2012-10-20 2:33

exploiting mistakes made by those that are ignorant to the proper use of cryptography

Name: >>2 2012-10-20 2:34

I meana respond to >>31

Name: Anonymous 2012-10-20 2:55

>>31

I want to say no. Steganography is about making information obscure. To find the information, you need to know where to look and how it is encoded. The ``where to look'' and ``how it is encoded'' form a weak private key if you will. Although this isn't a substitute for encryption, because ``where to look'' can be brute forced by performing analysis on every piece of information that could possibly contain steganography. And ``how it is encoded'' can be brute forced by trying many known encodings. If the encoded information is not encrypted, it can be reassembled.

You can use public and private key cryptography to encrypt your messages and then transmit them using steganography. Raw encrypted data is obvious to an ease dropper. But encrypted data within steganography takes more analysis to detect.

Name: Anonymous 2012-10-20 3:13

>>34
Steganography is used to hide the evidence of transfer.

For example, alternating in your mail synonyms of the same word, you can provide a binary stream.

Name: Anonymous 2012-10-20 3:17

>>34
encrypt your messages and then transmit them using steganography.
If Mossad finds that, they will rape your anus and you will tell them all your passwords.

Name: Anonymous 2012-10-20 3:35

>>35
I guess the ease of detection depends on how much information you are trying to pack. One bit or two per email would be impossible to detect. But if your needs demand more throughput, it will look more obvious.

Name: Anonymous 2012-10-20 3:39

>>37
Just send a few Bible chapters, matching you pattern.

That is how Rabbies encode "kill christian babies" message into Talmud.

Name: Anonymous 2012-10-20 3:48

>>36
And that's why you have two keys: one that decrypts to the original message, and one that decrypts to a plausible but fake one. If you use an OTP it's trivial and impossible to prove.
Two Mossad agents operating in the US in the '70s actually did exactly that.

Name: Anonymous 2012-10-20 3:48

>>36



come   and        get

me        bro      I'

m doing          it  

        now   as I   

                 type

 this   and     you'l

l     never          

   know              

                     

     what  I'm saying

               never!

Cryptography [PART I]

1 Name: Cryptography 2012-10-16 22:36

2 Name: exploiting ignorance 2012-10-16 22:42

3 Name: Anonymous 2012-10-16 22:48

4 Name: Anonymous 2012-10-16 22:53

5 Name: Anonymous 2012-10-16 22:54

6 Name: Anonymous 2012-10-16 22:55

7 Name: Anonymous 2012-10-16 22:56

8 Name: Anonymous 2012-10-16 23:02

9 Name: Anonymous 2012-10-16 23:04

10 Name: Anonymous 2012-10-16 23:05

11 Name: Anonymous 2012-10-16 23:33

12 Name: Anonymous 2012-10-16 23:41

13 Name: Anonymous 2012-10-16 23:51

14 Name: Anonymous 2012-10-17 3:22

15 Name: Anonymous 2012-10-17 9:56

16 Name: Anonymous 2012-10-17 10:07

17 Name: Anonymous 2012-10-17 11:31

18 Name: Anonymous 2012-10-18 1:09

19 Name: Anonymous 2012-10-18 2:30

20 Name: Anonymous 2012-10-18 11:40

21 Name: Anonymous 2012-10-18 12:46

22 Name: Anonymous 2012-10-18 12:48

23 Name: Captain Autism 2012-10-18 12:56

24 Name: Anonymous 2012-10-18 13:17

25 Name: Anonymous 2012-10-18 13:26

26 Name: Anonymous 2012-10-18 13:31

27 Name: Anonymous 2012-10-18 13:36

28 Name: Anonymous 2012-10-18 16:02

29 Name: Anonymous 2012-10-18 17:47

30 Name: Anonymous 2012-10-18 18:10

31 Name: Anonymous 2012-10-20 2:08

32 Name: >>31 2012-10-20 2:33

33 Name: >>2 2012-10-20 2:34

34 Name: Anonymous 2012-10-20 2:55

35 Name: Anonymous 2012-10-20 3:13

36 Name: Anonymous 2012-10-20 3:17

37 Name: Anonymous 2012-10-20 3:35

38 Name: Anonymous 2012-10-20 3:39

39 Name: Anonymous 2012-10-20 3:48

40 Name: Anonymous 2012-10-20 3:48

Name: Cryptography 2012-10-16 22:36

Name: exploiting ignorance 2012-10-16 22:42

Name: Anonymous 2012-10-16 22:48

Name: Anonymous 2012-10-16 22:53

Name: Anonymous 2012-10-16 22:54

Name: Anonymous 2012-10-16 22:55

Name: Anonymous 2012-10-16 22:56

Name: Anonymous 2012-10-16 23:02

Name: Anonymous 2012-10-16 23:04

Name: Anonymous 2012-10-16 23:05

Name: Anonymous 2012-10-16 23:33

Name: Anonymous 2012-10-16 23:41

Name: Anonymous 2012-10-16 23:51

Name: Anonymous 2012-10-17 3:22

Name: Anonymous 2012-10-17 9:56

Name: Anonymous 2012-10-17 10:07

Name: Anonymous 2012-10-17 11:31

Name: Anonymous 2012-10-18 1:09

Name: Anonymous 2012-10-18 2:30

Name: Anonymous 2012-10-18 11:40

Name: Anonymous 2012-10-18 12:46

Name: Anonymous 2012-10-18 12:48

Name: Captain Autism 2012-10-18 12:56

Name: Anonymous 2012-10-18 13:17

Name: Anonymous 2012-10-18 13:26

Name: Anonymous 2012-10-18 13:31

Name: Anonymous 2012-10-18 13:36

Name: Anonymous 2012-10-18 16:02

Name: Anonymous 2012-10-18 17:47

Name: Anonymous 2012-10-18 18:10

Name: Anonymous 2012-10-20 2:08

Name: >>31 2012-10-20 2:33

Name: >>2 2012-10-20 2:34

Name: Anonymous 2012-10-20 2:55

Name: Anonymous 2012-10-20 3:13

Name: Anonymous 2012-10-20 3:17

Name: Anonymous 2012-10-20 3:35

Name: Anonymous 2012-10-20 3:39

Name: Anonymous 2012-10-20 3:48

Name: Anonymous 2012-10-20 3:48