WinRAR: A Worthy Competitor for WinZip? Safety and Security Joseph Moran
Safety and Security
Another dreaded scenario is compressing a file for someone (or worse, for yourself) only to find out later that something went wrong and the file is corrupt or otherwise unreadable. To help avoid this, WinRAR offers a test feature that checks a compressed file and ensures it is valid and intact. This of course won't help you if a file is corrupted in transit, but it will guard against damage that might occur during the compression process.
To protect against damage that might occur after the compressed file is made, WinRAR lets you incorporate into it a recovery record of up to 10% of the file size. This redundant information can then be used to attempt repair of a damaged file, which would hopefully lead to salvaging most or all of the contents. (The addition of a recovery record does naturally inflate the size of the file.)
It's an established fact that viruses, worms, and other nasties can infiltrate your computer by hiding in compressed files. As a preventative measure, WinRAR will not extract any files with one of seven extensions that would make them potentially dangerous — EXE, COM, PIF, SCR, BAT, CMD, and LNK.
For an added level of protection, the application can also call your anti-virus software to scan compressed files. However, archives are not scanned automatically when they're decompressed — you must explicitly select the option to do so in advance. Also, although WinRAR successfully identified the installed anti-virus software (Norton Internet Security 2004) on one of our test machines, it wasn't able to detect the Corporate Edition of NAV on another. (Fortunately, you can manually specify the path to a scanner in this case.)
To protect the contents of files from prying eyes, WinRAR lets you encrypt and password-protect files, although ZIP files only get the standard ZIP encryption algorithm, which can provide protection against casual users but is too weak to stand up to determined attack. When encrypting RAR files, WinRAR uses the considerably more robust AES 128-bit encryption. This isn't quite as strong as the 256-bit AES supported by WinZip, whose encryption does of course apply to ZIP files. On the other hand, WinRAR gives you the option of encrypting not just file contents but also filenames and other attributes well.
To prevent inadvertent (or perhaps deliberate) changes to a compressed file without having to put a password on it, WinRAR offers a lock feature. Once a compressed file is locked, files within it can't be added, removed, or overwritten, though they will still decompress normally.
