Ganymed SSH-2 for Java is a library that implements the SSH-2 protocol in pure Java (tested on J2SE 1.4.2, 5, and 6). It allows one to connect to SSH servers from within Java programs. It supports SSH sessions (remote command execution and shell access), local and remote port forwarding, local stream forwarding, X11 forwarding, SCP, and SFTP. There are no dependencies on any JCE provider, as all cryptographic functionality is included.
Hardened Debian improves Debian GNU/Linux with high security and hardening features, hardened kernels and packages, DHKP, and other security related enhancements. It makes systems more difficult to compromise using common attacks such as race conditions, chroot jail escapes, and buffer overflows.
rrs is a reverse (connecting) remote shell. Instead of listening, it will connect out to rrs in listen mode. The listener will accept the connection and receive a shell from the remote host. rrs features full pseudo-TTY support, full OpenSSL support (client/server authentication and choice of cipher suites), Twofish encryption, a simple XOR cipher, plain-text sessions, peer-side session snooping, a daemon option, and reconnection features. It is known to compile and run under Linux, FreeBSD, NetBSD, OpenBSD, and QNX.
guard bash is a shell wrapper that will execute an authentication phase before any command is executed. It uses a secret (user owned) algorithm method, and has a per user customizable procedure. If you need to connect to your computer from outside of your safe environment, even if you use SSH, you are vulnerable to simple attacks like key sniffing or to more complex attacks against SSH. If you have more than just one authentication method, you can more safely log in your account from an insecure Internet host.