SafeDisc
SafeDisc is a CD / DVD copy protection from Macrovision . The term copy protection is misleading because SafeDisc does not prevent the copying of protected media, but only prevents the execution of protected programs from copied media. A distinction between the original medium and the copy is only possible if there are differences that can be read out by the CD drive. Modern burning software can create 1: 1 copies in connection with certain burners , which make it impossible for SafeDisc to differentiate between original and copy. The same basic weak point can also be exploited by drive emulation. For this reason, newer versions of SafeDisc keep a blacklist with burning software and software for drive emulation. So far, SafeDisc has 4 main versions with numerous sub-versions (as of May 2007). The current version is sold under the name SafeDisc Advanced . All versions of SafeDisc encrypt the protected program and only decrypt it if an original medium is recognized and authenticated. Since the required key is also stored on the medium, the copy protection can be permanently deactivated by decrypting the protected program.
Technology & versions
SafeDisc (1)
On the first 5% of the data structure of the medium there are around 10,000 unreadable (defective) sectors: They should abort or at least significantly delay the reading process with burning programs. Programs that do not have the so-called “intelligent detection and skipping of unreadable sectors” function need several hours to read such a CD.
SafeDisc-protected CDs can be recognized by the files in the table of contents (TOC):
- 00000001.TMP
- CLCD16.DLL
- CLCD32.DLL
- CLOKSPL.EXE
- DPLAYERX.DLL
- * .ICD (the original program file in encrypted form)
- * .EXE (has the same file prefix as * .ICD and contains the program loader and parts of the copy protection)
SafeDisc (1) represents a comparatively weak copy protection and was quickly overridden by burning programs.
SafeDisc 2
SafeDisc 2 also contains specially modified sectors . This copy protection cannot always be bypassed.
The features of a SafeDisc 2 protected CD include the files 00000001.TMP and 00000002.TMP listed in the table of contents (TOC). The latter file does not always exist. The SafeDisc 2 loader is located in the executable start file GAME.EXE. In addition, the data carrier contains unreadable bad sectors.
The basis of the copy protection is the standard Yellow Book CD format, which is used for CD-ROMs and mixed-mode CDs. When the CD starts, authentication is initiated via the SafeDisc Loader, which decodes and executes encrypted files. In addition, the digital ID is checked in the main channel data area. The digital ID consists of bad sectors and data that are in the pregap area. By definition, the pregap area is an area of around 2 seconds in front of the data track and does not contain any data. However, some burners store their signature there. With this signature it is possible to identify a copy.
Another protection is the EFM coding of the CD. Any user data can be translated into valid EFM words, but there are only 256 valid out of a total of 16384 EFM words. Invalid EFM words that were deliberately pressed onto the medium during production cannot be copied because the burner can only write valid EFM words. In addition, there are so-called "weak" sectors on a protected CD.
SafeDisc Advanced / SafeDisc 4
SafeDisc Advanced should also prevent the creation of virtual drives. In order to protect programs, Macrovision supplies special software that manufacturers can integrate into their programs and call up anywhere. As of this version, similar to StarForce and SecuROM 7.x, the protected game no longer starts from a SCSI drive (even SATA drives in AHCI mode are recognized as SCSI drives under Windows). This is to prevent the use of emulator software, which so far are only able to emulate SCSI drives. However, as SafeDisc does not use a driver like Starforce, the software can hide the drives from the copy protection. The “ Daemon Tools ” program, for example, has this capability .
SafeDisc 4 Advanced
SafeDisc 4 Advanced checks the ATIP of a CD / DVD. Information about the CD type is stored in the ATIP. Logically, a blank disc contains the specification CD-R, but only burners can read the ATIP. Nevertheless, SafeDisc 4 Advanced also includes such protection for CD / DVD-ROM drives. Where the ATIP code is on the CD-R, there is a SafeDisc code on a SafeDisc-4-Advanced-protected CD / DVD, which can be read by CD / DVD-ROM drives by briefly reading backwards (on Beginning of the CD). However, not all CD / DVD-ROM drives can read backwards.
The crack protection encrypts the .EXE or .DLL files so that the copy protection cannot be removed manually.
SafeDisc 4 Advanced works with blacklisting, i. that is, it looks for filenames like “ CloneCD ” on the hard drive ; if these are found, not even the original will work anymore. Emulating this version of DVD has only been possible since the "RMPS V2" (Recordable Media Physical Signature) function has been integrated in Alcohol 120% Version 1.9.6.46xx. With this it is possible to save the relevant information in the MDS file and burn it with Alcohol 120% or Daemon Tools Pro Advanced. Backup copies burned with RMPS only run on systems on which one of the two emulators is installed.
Individual evidence
- ↑ Digital protection mechanisms and their circumvention in the context of German copyright law. Retrieved February 24, 2019 .