Do I need to compress the archive with a password and encrypt the file names?

Question

rar

There is a RAR archive. Version 5. Weight 1GB.
They say that it is impossible to hack except by selection. At this point in time (2021).
I'm more concerned about something else, is it necessary:
​​1) to set the maximum compression or none at all? (heard the latter would make it harder to crack)
2) encrypt filenames inside the archive?

Answer 1

Depends on who we are protecting. If from the security authorities, then it is quite possible that the encryption will be cracked.

2) encrypt filenames inside the archive?

If archive headers are not encrypted (“encrypt file names” option is disabled), file checksums for encrypted RAR 5.0 files are modified using a special password dependent algorithm. This prevents third parties from guessing file contents based on checksums.

What is the "Encrypt File Names" Option?
If you set the "Encrypt file names" option, WinRAR will not only encrypt the file data, but all other sensitive archive areas like file names, sizes, attributes, comments and other blocks. This provides a higher level of security.
If you want to prevent third parties from drawing conclusions about the content of the archives based on the meta files, you should enable this function . Without entering the correct password, it is impossible to even view the list of files that have been encrypted.

https://www.win-rar.com/encryption-faq.html?&L=0

Answer 2

2) encrypt filenames inside the archive?

necessarily. Without this option, the contents of the archive (names, dates of creation, size!) can be seen even without knowing the password. Of course, if the files in the archive are 1.txt, 2.txt, 3.txt - there’s not much to understand what it is, but how many people rename it like this specifically to garbage?

Answer 3

1. Maximum compression increases the time for decompression slightly, but increases, complicating the selection by brute force.
2. Encrypting file names is very important, because if a large archive contains a file that is already known (for example, some well-known library or program that can be downloaded from the Internet, and an attacker receives an encrypted and decrypted file, which allows him to use there are already other methods for decryption, not direct enumeration.In this case, the attacker will not even understand what exactly is in the archive.
3. Ideally, use the solid archiving option in rar, since in this case data from the previous file is used to compress files, so there is no way to unpack a specific single file (except for the very first one), and if the first file in the archive is not yet small, this significantly increases the iteration time. In a normal non-solid archive, you can find some very small file and sort through everything on it.