Encfs creates transparent and overlaid encryption over any pre-existing filesystem. A perfectly normal directory in your filesystem looks like garbage, but when you mount it, upon providing password, you can read and write it un-obfuscatedly.
For first time creation there is a helpful...

Cross Platform Password Manager

Nmap ("Network Mapper") is a console utility for network exploration or security auditing. Many systems and network administrators also find it useful for tasks such as network inventory, managing service upgrade schedules, and monitoring host or service uptime. Nmap uses raw IP packets in novel

John the Ripper это быстрый взломщик паролей, в настоящее время доступен для многих видов Unix, Windows, DOS, BeOS и OpenVMS. Ее главная цель состоит в том, чтобы обнаружить слабые пароли Unix...