Recovering the password for a multivolume RAR archive

Summary

Before starting to recover a password for a multivolume archive in RAR3 format, Accent RAR Password Recovery combines all the volumes in a single file and then begins its attack of the new large RAR file.

For multivolume archives in RAR5 format, combining volumes is not needed. Any archive volume can be attacked.

Problem

Recovery of RAR passwords consists of three steps:

• Generating an encryption key from the password that we are testing.
• Decrypting the RAR archive with that key.
• Checking the integrity of one of the archive files.

So to check the validity of a password of an archive in RAR3 format, the program must completely extract one of the files (any of them, usually the smallest one) and check its checksum. If the file fails the integrity check, the password is incorrect and the cracker moves on to the next password.

This will continue, on and on, until the password is found.

But in the case of multivolume archives, all of the files in an archive may be divided among different volumes. Then all of the volumes must be united into a single archive.

Solution with AccentRPR

1. If necessary, Accent RAR Password Recovery  will offer to merge all volumes into a single file immediately after one of the archive volumes is chosen:

2. All that needs to be done is to select a place for storing it and a name for the combined archive:

3. Restart the process of recovering the password for the newly created RAR archive:

Conclusion

Accent RAR Password Recovery completely supports the RAR3/RAR5 format, including multivolume archives created in WinRar 2.90 and later.