Reverse Engineering- Author- Saikat Basu. As Wiki suggests, Reverse engineering (RE) is the process of discovering the technological principles of a device, object or system through analysis of its structure, function and operation. It often involves taking something (e.g., a mechanical device, electronic component, or software program) apart and analyzing its workings in detail to be used in maintenance, or to try to make a new device or program that does the same thing without copying anything from the original. It all started with an endeavour to analyse things, not while they were produced, but after they were actually manufactured. So, this process of analysing products, either hardware or software, was basically begun with the intension to change, the way, the things actually worked. This may be due to various reasons. The concept of reverse engineering is useful and relevant for both the White-hats as well as the black-hats. Well, many may think, who r dese guys? These r the two sets of hackers, dat I am talking about. I will introduce you to them sometime later. Well, for now, just do some googling about dem, if u really want 2. Now, its the white-hats who actualy, try to find out manufacturing defects in dem, and den try to sort dese so dat, in future productions, dese errors dont come.The black-hats on the other hand are the crackers, who try to break into systems based on dese backdoors by compromising dem to their own advantage.  As far as I know, all sorts of reverse engineerings are somehow related. Now let me come down to the basics. Let me start by giving a simple example of the concept, Reverse Engineering. Suppose you are writting a program in C. Then u compile and execute it to create an exe file for windows(I am not going into *nix now). So, you have created a product dats ready for deployment. Well, now let me ask a simple question. Has nyone of you ever tried to open an exe file not by double clicking, but by doing a right click and selecting Open with Notepad. Try dat if u have not yet done so. You'll find something dat looks lyk garbage. So, what we know now is dat we can open an exe in another way, but its useless. Well, now I ll teach u all a third way to open it. Have nyone heard about a dissassembler? May be not. Well, its a tool freely available on the net, dat helps you vew dese exe files and many others like dos exe, flash files etc. in readable format ,ie, as hex code or assembly code. I am giving a download link here.                                                                                                                                                                                               Now, after you have opened the file with tha Interactive Disassembler, in short, IDA, also called hex editor, all you need to do is know the basics of assmbly language programming and finer details about the internal architecture of the product, which may be the software program I was talking about, a bit earlier, or the flash files of a mobile. Till now I was taking about a simple exe file created by us using our good old frnd C. Now, its time to think a little bigger. Lets talk about our cell phones. How many of us use a cell phone today?? The answer is evident. And how many of them are engineers? Still the answer would be many. And now the simplest question. How many of them know or even try to, to actually find out how to change the way it works? This time the answer is a bit different. Its all about the desire to know. Now, returning to the topic, a fine example of reverse engineering is to actually change the way your phone works. May be changing the fonts, the types of dictionaries the look of contacts menu and so much. So, what you need is the firmware of the phone, basically, called the flash files. In simple words, these may be considered as system files of the phone, like the ones found in c:/windows/system32 or /etc/var/ directory? eh joking. Now you can get hold of these here                               Click here to get your flash files now.          So, now that you have got these, all that you have to do is that, simply load the files in the IDA that I gave you. Now the tough part begins, ie, anlysing the code.The code is presented both in hex and assembly. Now gather some technical knowledge about the architecture of the phone, and you are set creating your first reverse engineered product may be your own nokia or samsung cell phone. Hey wait, the same logic I gave applies equally to the firmware of any elctronic goods, an ipod, digital calculators and even your dialup modem. Well a modem is one of the most interesting things I have ever gone accross and I ll be talking about Modem Uncapping- somewhat hacking in another article. Bye for now. Leave your opinions and suggestions at deepbasu007@gmail.com