There’s no denying that Secure Shell Protocol (SSH) is the de facto tool for Linux server administration, but is it truly secure? While SSH is widely supported, fairly straightforward to use, and was built with security in mind, it’s far from perfect.
SSH, invented in 1995, is a cryptographic network protocol for accessing UNIX machines securely over an unsecured network. SSH uses a client–server architecture, connecting an SSH client application with an SSH server. It superseded Telnet protocol by adding encryption to prevent malicious actors from eavesdropping on network traffic and compromising data confidentiality and integrity.
Typical applications include remote command and shell execution, but any network endpoint can be secured with SSH. SSH is very important in cloud computing to solve secure connectivity problems to cloud-based virtual machines. Many popular products and just about every server deployment system integrates with SSH somehow. It is universally supported across pretty much all architectures and distributions, from Raspberry Pis all the way up to massive supercomputer clusters.