If you came here searching for the phrase "breaking rar encryption," the short answer is: "Impossible."
Here's the longer answer.
I get a lot of questions about password protected and encrypted archives. Some people ask, if other programs can extract encrypted archives created by BetterZip, others just want to get access to archives to which they lost their password (nudge nudge, wink wink.)
BetterZip can create encrypted archives that can only be extracted if you have the correct password. There are many other programs on every operating system that can extract these archives. The only exception on the Mac is, unfortunately, the BOMArchiveHelper, which is the archiver that ships with Mac OS X. So, yes, Mac OS X can create and extract archives without any extra software. No, these archives must not be encrypted. But there are other free alternatives. (You know that extraction is free with BetterZip, don't you?) On Windows there are 7-Zip, WinZip, WinRAR, and many others.
Basically, there are two kinds of encryption: Strong and weak. Latter is only there to keep your granny (warning: this only applies to the average granny who does not break crypt codes for fun) from stumbling over your collection of super secret stuff. If someone actually wants to break archives with the weak pkzip2 encryption, they probably will.
This is rather worthless if you want to secure some sensitive data to send them as attachment to an e-mail over the internet. Therefore, most archive formats (zip, rar, and 7-zip) support strong encryption with the AES method with 256 bit keys which is (according to US government standards) sufficient for information classified as TOP SECRET. Don't you feel a little james-bondy yet? Today there is no known way to extract the contents of AES encrypted archives without the password. This leaves only one way to "crack" such an archive: guessing the password. (The alternative - according to Dan Brown - would be to be a math genius working for the NSA. Worst book ever by the way. Yuck!)
So, my advice here: Make sure the password is not your first name, or that of your significant other, your dog's, or first born's, or any real word you can find in a dictionary. And make it longer than, say 6 characters, maybe even mixing in numbers and special characters like # or $. The method I like best is taking the first letters of each word in the chorus of one of my favorite songs, replacing for example the letter I by with the digit 1, or S by $, A by 4. That gives good passwords for everything, like the login to your Mac. Easy to remember, because you can sing along while entering the password. Of course, only in your head.
How do you encrypt an archive with BetterZip?
In the save panel drop down the button encryption method and select Strong (AES256). This will only be available when you choose an archive format that supports encryption. Tar, gzip, and bzip2 don't. Click the save button.
A panel will appear asking you for the password. Enter it twice and click OK. The OK button will only be active, if the two passwords match. This protects you from entering a password with a typo and never regaining access to your archive.
Now the archvie will be encrypted and saved. After the operation finished BetterZip will activate the small lock in the status bar to signal that the archive is encrypted.
One last word of advice: Please, don't encrypt an archive, put it in an e-mail and write "Hi Monty, here's the secret data. The password is hellfish. -- Abe." Tell Monty the password over the phone instead.
(4.9)
(4.6)
