At present, encryption recording technology and related products can be roughly divided into two categories: ① pure software processing; ② Soft and hard combination. Among them, pure software processing can be divided into three categories: directory/file hiding, directory spoofing and third-party software.
The so-called directory/file hiding, its principle was widely known as early as the MS-DOS era-by modifying the directory/file attribute bytes, it was hidden. However, due to the special process of CD burning and the disk reading and writing characteristics of Windows 9X and other systems, the object of this operation becomes a mirror file of the data to be burned, that is, such as. Hint and. Cif used in common combustion tools. In the specific operation, the corresponding attribute byte is analyzed and located by hexadecimal editors such as Ultraedit and Winhex, and it is changed to "04", and then burned after being saved.
The so-called directory cheating is to use the special structure of the mirror file to modify the actual display name of the directory to be kept secret, so that it is inconsistent with the actual operation name, resulting in abnormal file access, giving people the illusion of "disk problem" or "system problem" and confusing others. In addition, this method is usually combined with directory hiding to enhance the confidentiality effect.
The basic method of third-party software encryption is to re-encode or unpack the original data before or at the same time of recording, and put the decryption program in the automatic operation of the CD, so that the original data can be seen only after verifying the password. Otherwise, even if you can browse the CD, you will only see the processed "processed products". As for the specific implementation method, it is "the Eight Immortals cross the sea and show their magical powers." At present, there are many kinds of encrypted recording software on the market, such as CD-protector, SecureBurn, CryptCd and so on.
As for "soft and hard combination", it can be divided into three categories. One is to determine whether the CD information is available by judging the BIOS of the motherboard and setting the encryption point of the hard disk, but this will inevitably reduce the universality of the CD and the practical value of engraving the CD will be greatly reduced. Therefore, this technology is of little significance to ordinary users, and there are few such products on the market.
The other is to use "over-recording". There are two understandings of the so-called "over-recording". One is the recording that exceeds the nominal value, and the nominal value usually refers to the standard values: 74MIN@650MB and 80MIN@700MB. Due to the large diameter and radian of the outer ring of the optical disc, a lot of available physical space is left for recording pits. Therefore, encrypting records on the outer ring and setting encryption information points can not only increase the capacity, but also play the role of encrypting optical discs. Because the over-engraving part is completely carried out on the outer ring of the CD, the pit spacing and depth are not less than the minimum specified in the orange book, so it will not affect the normal reading of the CD-ROM drive in theory; Another understanding refers to the large-capacity optical disc recording that conforms to the provisions of Orange Book 2(CD-R optical disc standard protocol), such as the super-recording function of 90MIN@800MB and 99MIN@870MB. Over-engraving needs the support of burner and software, and also has certain requirements for the quality of CD-R discs.
The third is to make a fuss about the storage form of optical disk data by using a special optical track writing method. This technology is usually used to realize "copy prevention" of optical discs. Many genuine software CDs cannot be copied, even if they are copied, they cannot be used. That's the reason. Typical representatives are: Free Lock, Safedisk, etc. For example, Safedisk mainly realizes "copy prevention" of optical discs by verifying digital signatures and data protection coding.
Below we will introduce several common encryption methods and the corresponding cracking methods in practical application.
Encrypted article: Don't use my CD.
When it comes to CD encryption, you may all know some methods, such as prompting for a password when using a CD, hiding the real path of the source file, and generating a very large file that cannot be copied. , you can make all kinds of encrypted CDs. Let's first look at how to encrypt a CD.
Add a password to the CD.
Adding a password to a CD is the simplest encryption method. When viewing this CD, you must enter the correct password, otherwise you will not be able to browse and use any files in the CD. Because this encryption method is simple to operate, but its security is relatively strong, it is very suitable for novice players.
SecureBurn allows you to add a password to a CD. Its biggest feature is that the CD is password-protected before it is officially burned, and then the CD with password protection can be directly obtained through the built-in burning function of the software.
1.SecureBurn can be downloaded from/down/cdp3setup.exe. Although it is not complicated to make an encrypted CD, the program only has encryption function and does not provide CD burning function. Here we use Nero software to burn CDs.
1. After running CD-Protector, set options such as "File to Encrypted pt", "Custom Message" and "Phantom Trax Directory" in the window shown in Figure 3, and enter a two-digit string from 00 to FF as the encryption key in the "Encryption Key" dialog box.
2. After completing the above settings, click the red "Accept" button. At this point, CD-Protector will encrypt the selected source file. After encryption, you can see that the source file icon has been replaced by the unique logo of CD-Protector, and an additional audio file has been added.
3. Then run the Nero burning program and create a new audio CD, but there are some targeted settings for the program:
① Do not select "Write CD text on CD" in the Audio CD tab.
② Check "Remove the mute at the end of *". "cda tracks" and "Cache tracks on hard disk before burning" in the "CDA Options" tab.
③ Remove the "Complete CD" item from the "Burn" tab.
After completing the above settings, click the "New" button to create a new task, and drag and drop the audio file just made by CD-Protector into the window where the audio track is recorded.
4. After burning, burn the audio file obtained by CD-Protector again according to step 3, that is, burn the same audio file twice in this way. Maybe you will feel strange: why do you want to burn the same file twice? This is because CD-Protector adopts track encryption technology, and determines whether the file can be used by detecting the existence of tracks.
5. Then create a new ISO task in Nero, select "Stratsession Disc" in "Multi-Session", and then drag and drop all files generated by CD-Protector except audio files into the data recording window to start recording. The recording options need to be the same as those set when recording audio tracks.
6. After burning, we get an encrypted CD. At this point, we can view this CD through the "record → view tracks" command in Nero (Figure 7). As you can see here, the same audio file is very different after being burned twice, which is why it needs to be burned twice.
7. Finally, put the encrypted CD into the CD-ROM drive. At this point, the original executable icon has become a unique icon of CD-Protector. Double-click it to run the program normally. However, since CD-Protector encrypted CD is composed of two audio tracks and one data track, the encrypted executable file in the data track will read the audio track on the CD when it runs, and if it corresponds, it will continue to run, so copying this file to the hard disk will cause an error message. How about, so that the files you store in the CD are safe.
Make personalized encrypted discs.
Through the above operations, we have mastered several common CD encryption methods. Here, I recommend a CD encryption expert who can make personalized encrypted CDs. As an encrypted CD software, CD encryption master can directly modify CD mirror files, such as hiding the directories and files in CD mirror files, turning ordinary files into oversized files, or turning ordinary directories into file directories, so with its help, we can easily make our own personalized encrypted CDs.
The CD encryption master can download it from/gphy/gphynew.exe. Before using it, we need to make important files into CD image files in ISO format in advance, and then encrypt them through the CD encryption master.
After running the CD Encryption Master, click the "Open Image File" button in the toolbar, load the ISO file to be processed, and then you can see the window as shown in figure 17. There are four directories: file directory, hidden directory, normal directory and autorun, and three files: autorun.exe(2GB file), autorun.inf and description.txt Although there are many ways to convert these files, you can easily complete them by selecting the corresponding files and clicking the corresponding button on the toolbar.
1. Hide the directory or file in the CD image.
Select the directory or file to hide, and then click the Hide button. After the image file is burned into a CD, the hidden directory or file will not be visible in the browser.
Note: Do not hide autorun.inf and autorun.inf, otherwise the CD will not run automatically.
2. Turn the file in the CD image into a very large file.
Right-click the file to be enlarged, and select to become a super-large file. When the image file is burned into a CD, it will be displayed as 2GB when viewed from a browser!
Note: Don't turn autorun.inf into a very large file, otherwise there will be errors such as illegal operation.
3. Change the directory in the CD image to a file.
Select the directory to be converted into a file, and then click the "Convert Directory to File" button. After the image file is burned to a CD, the directory will be displayed as a file.
4. Make personalized encrypted CD.
After hiding all the directories and files to be encrypted, or changing the directories into files, click the "Write CD Password" button, then select the password form, the program to be run after password verification, and the CD icon, and enter the password in the CD Password dialog box that pops up (Figure 18). Burn the mirror file into a CD-ROM and verify the password before accessing the hidden directory, hidden file and file directory.
Because the CD encryption master is powerful and easy to use, it is suitable for friends at all levels to encrypt CDs.
References:
The above article is taken from Zhao Jiang Computer News,No. 17, 2003, for reference only!