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Hacking Webpages?

  1. Mar 14, 2007 #1
    Does anyone know how to? I dont mean crackers. Its hackers I wanna talk to. Those who get it, know the difference. Whats net security all about? How do encoding/decoding algoithms work? How can you compress information and still retain the quality of it?

    I know avi/mpeg/vcd/wmp are all codecs which do this, but whats the theory behind it? How is it possible? I thought that the net information content is a constant, so how can you encode something, compress it, and then decode it to get all the information back?
  2. jcsd
  3. Mar 14, 2007 #2
    are you talking about lossy or lossless

    here is an example of encoding http://en.wikipedia.org/wiki/LZW

    really your just changing bit patterns into shorter ones.
  4. Mar 14, 2007 #3
    which of those questions are you looking for answers for? Most compression tools/codec's work by finding repeating patterns and expressing them in a smaller amount of data. Compression is exactly that, taking something and making it smaller. Yes, if you read light_bulb's link you'll find theres compression types that intrinsically involve poorer quality but at the same time there's plenty of clever ways to sustain quality whilst reduce size. It's really down to the inefficiency of the original format.
  5. Mar 14, 2007 #4


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    It seems you're confusing the operation of the world wide web with the operation of a video compression scheme. In reality, they have nothing at all to do with each other. You can look up information about video codecs all over the web. You might want to look up MPEG on Wikipedia.

    The short answer is that any form of information has some inherent redundancies in it. In the case of english text, the fact that q is almost always followed by u is a form of redundancy. In the case of video, many frames with essentially the same content (i.e. a blue sky in the background) contain a great deal of redundancy.

    The point of all data compression schemes is to eliminate as much of this kind of redundancy as possible.

    - Warren
  6. Mar 14, 2007 #5
    Maybe what he is confusing it with is how data is transmitted with hardware. Some hacking techniques might require knowing how the web interact with network hardwares but i think that most of them only require knowing software manipulation.

    When hacking the web you need to know how the software of security work. Then if you know that there are some weak spots often called 'holes' or 'gaps', is where a hacker would usually take advantage of.

    Or maybe you are trying to use your knowledge of video compression and relate it with data encryption for security? One of the most common ways to bypass password security is by exhaustion where people write softwares that throw automatic generated passwords. But this kind of method is not very useful since what they have to do is to restrict the number of errors per minutes. Or something like if you inputted the password wrong 10 times, you will have to wait for 20 minutes before you can send any log in information.

    Also this kind of hacking is very easy to detect. Good luck though. Anything interesting you learn, don't mind sharing it with me. :rolleyes:

    Edit: When important information is sent over the web, they don't use loosely compression like videos. In this case, what the encryption in information does is that changes the content of the message into something that is not readable or at least not easily or directly until it is decoded. Some of the theoretical methods are similar to the audio/video compression but the sizes does not necessary become smaller like audio/video compression.

    For example to read this message replace every 'hou' with a space for easy readability:


    I think that you what to learn is cryptography.

    Last edited: Mar 14, 2007
  7. Mar 14, 2007 #6
    No, that is simply brute force, not very sophisticated.

    Advanced hackers would, for instance, target a frequently downloaded utility or program from the web by including a virus and redistributing it. Such a virus could install for instance a Trojan horse routine that starts up, hidden of course, everytime windows starts up. Such a program, when running, then loads and installs various software from the hacker's machine. For instance a key scan program, such a program collects username and password keystrokes from say Internet Explorer each time the user goes to a secure website to do things like banking or online trading. The results, with the associated websites, is then returned to the hacker's machine.

    Moral: always use a good anti-virus program and have a firewall (in addition to the XP firewall.

    And super sophisticated hackers go lower level, by installing root kits. Root kits rewrite low level routines such a disk or network reads and writes. Higher level programs, anti-virus software, and even Windows XP have no certainty anymore of what is really happening under the covers. Everytime say a disk write is requested, it could perform the action and, in addition to that, do something else that remains undetected, since the disk read is also rewritten, rewritten in such a way that all the "niceties" are hidden. The same could happen with network read and writes.
    Scary huh?
    Last edited: Mar 14, 2007
  8. Mar 14, 2007 #7


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    I believe the original poster was looking for "hacking" information -- that is, information about the depths of computer systems -- and not "cracking" information, as in information that could be used to break into computer systems.

    Please note that we cannot have any specific discussion about breaking into computers on this forum. Keep it general.

    - Warren
  9. Mar 14, 2007 #8


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    A note on compression: for some applications, such as compressing documents or other data where integrity is critical, the compression is done without loss by identifying repeating patterns (as already said). But for images, video and sound, most compression schemes do involve significant loss of data. But as it turns out, you can cut out upwards of 90% of the information from a video stream, for example, and not notice. Our eyes just aren't that good.

    Probably the simplest compression is jpg/mpeg, which finds areas where the colors are close to each other (such as a flat blue sky) and makes the colors identical. As you up the compression, it becomes very noticeable, but you can cut a pretty huge fraction of the data before that happens.
    Last edited: Mar 14, 2007
  10. Mar 14, 2007 #9
    I didn't say that the software which generate passwords are 'sophisticated', i just said that it is 'common'. But yep, it is completely brute force and easy to guard against like i mentioned before.

    Sorry about your moral for pc protection, but i don't use any protection software at all because it takes memory and slow things down (especially since my pc is not a fast one). When the times come, i just format everything and install all the softwares again. Besides, i never shop online or have any personal info in my pc.

    Last thing is that even though hackers do use really evil methods as writing trojan and viruses, it only hack user pcs. Unless i am wrong, the question says how to hack online web pages. Spywares are excluded as well since it is from a web page to a user pc rather than user pc to web pages.

    Although teaching how to hack is forbidden it is still a very interesting subject. But still, there is nothing i can teach since i never hacked before.
  11. Mar 15, 2007 #10
    I know a bit about brute forcing. But if you have 128 bit encryption, wouldnt that take you a couple of months with a normal computer to break the encryption?

    But more to the point, over the web, how is information transferred?
  12. Mar 15, 2007 #11
  13. Mar 15, 2007 #12
    What exactly is hacking?
  14. Mar 15, 2007 #13
    Thats what I thought to.
    The word hack is supposed to refer to someone who is an expert in programing, and understands the "internet" with reference to open standards etc. The media seems to think it means a cracker, someone who breaks into computers and steal information.
  15. Mar 15, 2007 #14
    Hmmm windows and weak could produce a lot of pages of info. Anyways every OS has ts weakness. But for the most vulnerabilities in windows are buffer overflows. Let me explain whats a buffer overflow. Lets say u create a char array of size 50.
    char buffer[5]; \\ in c++ Next you do something to cause the program to have a buffer overflow( you input a value that is too long ;etc)
    What happens is that the program would try to manipulate data that it thinks is its but its not. It overwrites thing that are on the ram
    for example buffer[5] = "dfdsffddsfdsf" \\ oh oh we have more than 5 character that we are writing to buffer . This would cause unusual problems and most likely cause it to crash. You can also use it to run other programs are etc..

    check this link out its on bufferoverflows.. very detailed
    hope i helped
  16. Mar 15, 2007 #15
    Hacking is the act of 'infirtrating' or 'breaking' into another computer or system without authorization.

    Cracking in the other hand, does not only infiltrate. Cracking also changes the configuration of the system to the one the he/she wants.

    So a hacker might or might not steal information after getting inside a system, and will not modify anything from the original settings.

    However, a cracker is a hacker that leaves a malicious code like virus, trojan or whatever. A cracker might not infiltrate a system manually while the hacker does it in real time. The cracker rather hack systems using the malicious code he/she has spread.

    Therefore, the cracker usually needs to know more about programming while the hacker more about (hardware to software, software to hardware, software to software, hardware to hardware) interactions. Some crackers might not crack systems but only small software applications.

    So a hacker might be a cracker depending on his aim. And a cracker might be just a programmer who creates a code for his own purpose.
    Last edited: Mar 15, 2007
  17. Mar 15, 2007 #16


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    Common techniques involve SQL injection and Cross Site scripting. There are also harmless "site hacks" which you can implement with some client-side code (i.e. javascript), such as what ChickenFoot for FireFox offers.
  18. Mar 15, 2007 #17
    Right! How could i forget the most important part of web data transfer. SQL! Most of the data transfers are done via database that use SQL commands. And yep, security is often done in the scripting side like Job said.

    Anything else not mentioned yet?

    Edit: Of course there are also programing languages that work on the security for the web. Many programming languages include Java, C#, Perl, Ruby, etc.
    Last edited: Mar 15, 2007
  19. Mar 16, 2007 #18
    I know a bit of C++. How what would i have to do to cause a buffer overflow? Before assigning memory to a variable/array, doesnt the OS check if that much memory is availaible or not?
  20. Mar 17, 2007 #19
    mac, unix, novell are a lot more stable compared to windows os's thats why 90% of viruses are built to run on windows only
  21. Mar 17, 2007 #20
    I know a bit of SQL too, but what the heck are SQL injections?
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