4.7. Security Enhanced Communication Tools

over the network.

• OpenSSH — A free implementation of the SSH protocol for encrypting network communication.

• Gnu Privacy Guard (GPG) — A free implementation of the PGP (Pretty Good Privacy) encryption application for encrypting data.

OpenSSH is a safer way to access a remote machine and replaces older, unencrypted services like telnet and rsh. OpenSSH includes a network service called sshd and three command line client applications:

• ssh — A secure remote console access client.

• scp — A secure remote copy command.

• sftp — A secure pseudo-ftp client that allows interactive file transfer sessions.

It is highly recommended that any remote communication with Linux systems occur using the SSH protocol. For more information about OpenSSH, see the chapter titled OpenSSH in the Red Hat Linux Customization Guide. For more information about the SSH Protocol, see the chapter titled SSH Protocol in the Red Hat Linux Reference Guide.

	Important
	Although the sshd service is inherently secure, the service must be kept up-to-date to prevent security threats. See Chapter 3 Security Updates for more information about this issue.

For more information about using GPG, see the appendix titled Getting Started with Gnu Privacy Guard in the Red Hat Linux Customization Guide.