Now its easily understandable why password standards are raised and enforced as any weakness makes brute force attacks more and more likely to be successful.
Conclusion: Going for a 8-char Unix password brute force on a PC is still tough. :) But 5- or 6-char Unix passwords are a piece of cake for anybody and should not be used! Numbers and special characters should be utilized in passwords to vastly increase the search space. Passwords should not be words found in dictionaries, not even with slight alterations. Alternate, slower computing password encryption schemes (i.e. MD5) should be used. Or, maybe, passwords should be abandoned at all, in favor of safer technologies. Recent development of "Rainbow Tables" allow to circumvent the password computing and can search through huge, pre-sorted password hash files at I/O speeds. Thanks to Hale www.deviance.org as the original author of viper.pl and to the authors of UFC-crypt at the Free Software Foundation. Viper is freeware provided the original author and source information remains. <Download Here>