What is SSL, TLS and SSH

Although it may seem to us that it is now when communications through technological means should be more secure than before, counting on the fact that there has been a kind of "age of innocence" of InternetThe truth is that at all times there has been the danger that someone will read our messages or virtually break into our computers.

That is why, in one way or another, more or less efforts have always been made to ensure that communications are secure. and, for this, a series of protocols and technologies have been created that help us to guarantee integrity and confidentiality.

SSL and TLS are, respectively, the original and the successor of a cryptographic protocol used to secure communications in telematic networks, mainly the Internet.

What SSL did (Secure Sockets Layer) and continue doing TLS (Transport Layer Security) more efficiently, is to encrypt communications through the use of cryptography in various online services, such as email or the web.

It is an Internet standard, developed, maintained and recognized by the organisms of technical management of the network of networks, with which thing is universal, independent of manufacturer and whose use is provided to any solution developer who works creating software and services in Internet.

The history of both protocols dates back to the mid-1990s, when SSL 2.0 began to be used (version 1.0 was never made available to the general public).

TLS 1.0 is an improved reimplementation of SSL 3.0, with enough differences that the two are incompatible with each other.

The differences between TLS and SSL is that the first improves the second by correcting vulnerabilities of security that have been found in SSL, and that in TLS the client is authenticated, while in SSL not.

This last detail is very important, since it ensures that, in a "conversation" between programs and services over the Internet, both the client as the server they are who they say they are, and that there is no one "listening" to the communications in between.

In contrast, in SSL, someone could intercept the communications and impersonate the client, since there was no verification of the identity of this, only in the case of the server it was verified.

SSH (Secure SHell) is a program that allows us to communicate, through a command line, with a remote server in a secure way

And it does, as in the previous case, relying on cryptography to encrypt communications exchanged with the server, so that no one can get the information from the packets that are crossed Between both.

It is a tool present in the vast majority of operating systems today, since it allows the administration remote and simplified from a server.

Usually, we have tools that work on the web, providing an environment graphic, but these are slow and depend, for their execution, that various elements are running on the server, such as a web server.

On the other hand, SSH only needs its own server, very simple and occupying few resources, and does not even require a graphical environment, with which we can use it in the simplest environments.

That it is a command line environment means that we must know the list of orders accepted by the operating system of the computer to which we connect.

The system is the same as the old MS-DOS for home PC computers before the arrival Windows, and replaces Telnet, another program that used to do the same, but did not include the safety added cryptography for communications.

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