Manual Implementation of Anti-copy of Disc Data

Manual modification of the disc data can prevent copying, which can also be encrypted. The required tool has the ISO format file of your CD and the UltraEdit modification tool. Modify the Data byte function before modification.

(Different bytes of data stored in the CD image file and the corresponding function List)

Byte Function
01 directory Length
02 extended attributes
03-10 file length location
11-18 File Size
19-25 file creation date and time
26 file attributes
27 file unit size
28 file staggered gap size
Capacity sequence number 29-32
33. File Name Length

The key is 11-18 bits. After 11-18 bits are modified, the file size will be changed and the anti-copy effect will be achieved.

My toolsNc.exeFor demonstration, and has been madeNc. isoFormat File.

Use UltraEdit to Open nc. iso, search for "nc.exe", and search for the file whose name you modified. And select "Search ASCII"

Find NC. EXE in the corresponding window on the right

Find the hexadecimal method corresponding to the point before the NC on the left. This 06 is 33rd bits, and the file name length. In the above comparison table, we can see that we want to modify the 11-18 bits. Now we have found 33 bits, so we can count up to 18 bits.

We can find the hexadecimal (00 6E 00 00 00 00 00 6E 00) corresponding to 11-18 bits. We can see that this string of characters is 11-18 bits, the file size can be changed by modifying these characters. We found that these characters are symmetric (00 6E 00 00 00 00 6E 00), that is, you must modify them in a symmetric manner. Change 6E to 00 on the left, and change 6E to 00 on the right. Otherwise, errors may occur. These modifications have not been completed yet. We need to modify the next one. We can pull down the window and only pull down. We cannot use search.

Find the wide file name corresponding to nc.exe in the right. The file name you just found is a narrow file name, and the wide file name cannot be found by searching. We found that many points have been added to the file name. Find the second point before N. Note that it is the second one.

N The left vertex is null, which is the corresponding 33 bits. The number is as high as 11-18, and the hexadecimal value is modified. It should be noted that the file size you modified above should be changed to the same one below. To prevent file errors.

Finally, you will find that the ISO file will become larger or smaller (depending on the hexadecimal file you modified ). This ISO file cannot be copied when it is burned to a CD. If you copy the file, an error is returned. This achieves a certain degree of anti-copy and encryption. Finally, you can modify the 11-18 bits of the wide file instead of the 11-18 bits of the narrow file name. However, we recommend that you change them to the same one for standardization and error prevention purposes. Another point is that we recommend that you do not modify the file size too large. Otherwise, the program may fail to run. We recommend that you back up the file before modifying it.