英国萨里大学\University of Surreydissertation指导：Crack and Protection of Software

1 Introduction

   Development of software, especially when used for commercial purposes , the registration number and activation code is very important, unregistered users will add some restrictions , such as the number of days delay , not registered screen and so on. But now the software crack technology is very powerful, has a variety of domestic and foreign large-scale software registration mechanism , but also continue to be cracked , the state has repeatedly intensify efforts to combat illegal software publications , supporting legitimate software , but the actual effect is not ideal . Most software vendors chose to buy encryption products or encryption technologies to protect their software , encryption software protection is generally divided into soft and hard encryption.
研发软件时，特别当用到经济活动用场时，注册码和拿获码是十分关紧的，未注册的用户会加上某些限止，如运用上天的安排，延缓，未注册银幕等等。不过如今的软件破解技术非常坚强雄厚，各种国里外大型软件都有注册机制，却同时也不停地被破解，国度一次又一次加大力量，打压不合法软件出版物，帮扶正版软件，但实效果并不理想。

2 , the common software crack method

   First let us look at break of several important professional terminology.
(1)断点，所说的断点就是手续被中断的地方，中断就是因为有特别事情发生，计算机暂停现时的担任的工作，转而去执行额外的担任的工作，而后再回返起初的担任的工作接着执行。

   ( 1 ) breakpoints, the so-called breakpoint is the program where it was interrupted , the interrupt is due to exceptional events , the computer suspend the current task , turn to perform additional tasks , and then return to the original task continues execution. Decryption process is to wait until the program to get our input and the correct registration code and registration code ready when comparing it to break down, and then we analyze the program , find the correct registration code.

   ( 2 ) airspace , the so-called program of airspace , is the program its own territory the site , which is our own program to crack the program code location. The preparation of each program are no fixed pattern , so we need people in the program when you want to cut interrupt program , you must not rely on specific procedures set breakpoints, that is, we set a breakpoint should be used for each program will be to things.

  (3) API, the Application Programming Interface shorthand , we called Application Programming Interface , is a large collection of system-defined function , which provides access to the operating system characteristics of the method . API contains hundreds of application calls functions that perform all the necessary operating system-related operations, such as memory allocation, the output to the screen and create a window , etc. , WINDOWS API-based programs to achieve and systems to deal with. No matter what the application , its underlying ultimately by calling various API functions to achieve a variety of functions .

   Understand the above three jargon , we look basic software cracking method.

2.1 brute force method . This is the most common and easiest way to crack , cracker direct use editing tools such as ULTRAEDIT-32 on an executable file to be modified , ie by modifying the program source files can attribute to achieve crack purposes. Some components in the authentication user registration information and registration code , if the user enters the information and software registration code via an algorithm to generate equal , the program will successfully registered , otherwise registration failed.

   2.2 using the algorithm Fillmore . Algorithm Fillmore is to analyze the software license algorithm based on making out a way to automatically generate software license program . So the software algorithm is very important, general software authors themselves write , easy to use software sales . Such software encryption feature is a registration code can only be used on one computer , and the computer as a one- binding. The first step is to run the trial use of the software, get this station machine software machine code , and then the algorithm Fillmore count number registration, then use the algorithm Fillmore directly calculate the appropriate registration code , and finally counted out registration code direct registration .

   2.3 Using Memory crack . We know all the programs that are running the data loaded into memory all have to go , software registration code during the certification process when there will be a comparison , so we only need to know the registration code to crack the software memory address, achieve their goals . The advantage of this approach is to not have to spend a great effort to master the software registration code algorithms, very save time writing memory Fillmore . First step is to load the memory RI , and through it to get a true memory software registration code , or modify the memory of some software-related data , to achieve the purpose of cracking software . There are two kinds of ways, first get the registration code directly from memory , the second simulation in memory of the registration process of the operating environment .

   2.4 patch crack method and file Registration Act . Patch crack method refers to the relevant patches to modify the software in order to achieve the purpose of cracking software . This method is generally cracked software validation registration code or time , basically modify the original program 's judgment statements. Such procedures probationary period is one month , you can put out this modification to achieve the purpose of infinite use . File Registration Act is to register the software contents into a document, in order to facilitate their own or someone else use it to register , there are registry registration file guide and guide people in two ways.