communication and hacking - Mrs-oc

sunflowerplateΤεχνίτη Νοημοσύνη και Ρομποτική

21 Νοε 2013 (πριν από 3 χρόνια και 8 μήνες)

67 εμφανίσεις

Communication Technology

How do we communicate and store information in the modern world?


How can our communications and data be interrupted, changed, lost or stolen?


How can we protect our communications and data?

And hacking

Why have hacking contests?


T
he
computer is deep and complex in its
function. There's a lot going on beneath
the games, music, and internet, but this
is something that many do not realize.
Though complex, it is comprehensible
even down to its lowest levels, and
making the effort to understand it is a
rewarding enterprise
-

there is joy in
discovery, and there are discoveries to
be had from the machine.


In
the course of learning
to hack, you
will
also pick up an understanding of
basic cryptography and what goes on
when
you open
a file, execute a
program, or browse the web, as well as
familiarity with some handy tools.


Not enough people understand how to protect our important data or how to uncover
potentially dangerous information left by others. Computer security is a rapidly growing field.

First, understand how data is stored


Binary code


Pixels of color for images


Notes for sound


ASCII or Unicode for text


HTML for web pages

(with CSS and JavaScript, etc.)


Executable code

for programs

pictures


EXIF data:



ExifTool

Version Number : 8.34 File Name : photo.JPG Directory : C:/Documents and
Settings/user/My Document s/Downloads File Size : 349
kB

File Modification
Date/Time : 2010:10:19 14:05:39
-
06:00 File Permissions :
rw
-
rw
-
rw
-

File Type : JPEG
MIME Type : image/jpeg JFIF Version : 1.01
Exif

Byte Order : Big
-
endian (Motorola,
MM) Image Description : Back Camera Make : Apple Camera Model Name : iPhone
Orientation : Horizontal (normal) X Resolution : 72 Y Resolution : 72 Resolution Unit :
inches Software : 4.0.1 Modify Date : 2010:10:19 14:00:52 Y
Cb

Cr Positioning :
Centered Exposure Time : 1/146 F Number : 2.4 Exposure Program : Program AE ISO :
80
Exif

Version : 0221 Date/Time Original : 2010:10:19 14:00:52 Create Date :
2010:10:19 14:00:52 Shutter Speed Value : 1/146 Aperture Value : 2.4 Metering Mode
: Average Flash : Off, Did not fire Focal Length : 3.9 mm Subject Area : 1295 967 699
696
Flashpix

Version : 0100 Color Space :
sRGB

Exif

Image Width : 1296
Exif

Image
Height : 968 Sensing Method : One
-
chip color area Exposure Mode : Auto White
Balance : Auto Scene Capture Type : Standard Sharpness : Hard GPS Latitude Ref :
North GPS Longitude Ref : West GPS Time Stamp : 14:00:46.81 GPS
Img

Direction Ref :
True North GPS
Img

Direction : 32.52336904 Image Width : 1296 Image Height : 968
Encoding Process : Baseline DCT, Huffman coding Bits Per Sample : 8 Color
Components : 3 Y
Cb

Cr Sub Sampling : YCbCr4:2:0 (2 2) Aperture : 2.4 GPS Latitude :
45
deg

14' 58.20" N GPS Longitude : 121
deg

39' 4.80" W GPS Position : 45
deg

14'
58.20" N, 121
deg

39' 4.80" W Image Size : 1296x968 Shutter Speed : 1/146 Focal
Length : 3.9 mm Light Value : 10.0

If you magnify any picture enough you will see the separate
dots of color ( pixels) but along with the visible picture is
invisible information stores in the same file that tells where,
when and with what the picture was taken.

Pictures are also great places to hide
data


http://
en.wikipedia.org/wiki/Steganography



writing hidden messages in such a way that
no one, apart from the sender and intended
recipient, suspects the existence of the
message









An example showing how
terrorists may send hidden
messages. This avatar
contains the message
"Boss said that we should
blow up the bridge at
midnight." encrypted with
mozaiq

using "
växjö
" as
password.

Cryptography


techniques
for secure communication in the
presence of third
parties

Hackers


2.1

White hat


2.2

Black hat


2.3

Grey hat


2.4

Elite hacker


2.5

Script kiddie


2.6

Neophyte


2.7

Blue hat


2.8

Hacktivist


2.9

Nation state


2.10

Organized criminal gangs


2.11

Bots


There are many different reasons for hacking. Some good,
some bad. But you can’t protect a system unless you
understand what attacks you need to protect against.

picoCTF

2013 hacking contest


http://
www.picoctf.com/learn


April 26th 2013
-

May 6th
2013


Toaster Wars



We recommend that, prior to the competition, each of the following languages is familiar to at least one member
of each competing team.


JavaScript

and

HTML


Python


Reading

C
. The basics of Java and C are sufficiently similar that anyone in a Java
-
based computer science course
should be fine in
picoCTF
.


Using the UNIX command line.


There are a lot of great web resources for leaning these languages and more about programming in general. You
should
google

around to find an introductory tutorial that you like! As some starting recommendations:

The
official Python tutorial

is excellent;

Codecademy

has tutorials for a variety of languages;

Khan Academy's CS
course

is taught in JavaScript;

Udacity's

CS course

is taught in Python; and

Coursera

and

MIT
OpenCourseWare

have great full
-
length courses for most languages.


There are also some ongoing
wargame

exercises which would excellent practice for
picoCTF
. Many of these get to
be quite challenging; don't be discouraged if you find any of these too difficult.


Smash the Stack

(online exploitation exercises)


Crackmes.de

(reverse engineering challenges)


Netforce.nl

(web exploitation and cryptography)


Other resources


hackThisSite.org