What is SSH ? | SSH Port | SSH Port Number | Use Of SSH | SSH vs VPN
Secure Shell (SSH) makes your transfer very secure.
Early men communicated with each other using symbols, and so do we. The difference is that those symbols were physical, but our symbols are digital. The development of technology introduced the internet, and since then, the world is communicating digitally.
We started transferring data and information with each other. With evolving technology, the mindset of people evolved, which also introduced security issues as a con.
Back in 1969, Telnet evolved as a technology where we can control two computers at the same time. But the primary concern of using Telnet was security.
Technology always evolves with the solution of an existing problem, so in 1995 Tatu Ylönen came up with a solution to the security issue in the form of Secure Shell.
This article will help you to understand SSH in a better way:
What is Secure Shell? What is SSH?
SSH or Secure shell or secured shell is widely used in the IT sector. It is a cryptographic secure network protocol that makes a tunnel on an insecure network so that you can transfer your document from Client to server and server to Client.
To understand it better, let’s take an example:
Suppose you live in a sharing apartment with multiple numbers of people. In that case, you cannot be sure that the data which you are downloading or uploading on the server is safe. But if you use SSH, then it is secured with the help of cryptography.
What is cryptography?
Cryptography is a technique that converts your standard data into machinery codes that need a key to be decoded. In other words, cryptography converts a plain text (anyone can understand that) into ciphertext (needs a key to decode). It works between two people, only Client, and server.
A client uploads the data to the server in encrypted form, which is further downloaded by another client and is decrypted using a key.
Remote login using SSH:
SSH or Secure Shell is used for various purposes among which Remote Login is a major one-
What is remote login?
A login that allows a user terminal to connect to a host computer via a network or direct telecommunications link, and to interact with that host computer as if the user terminal were directly connected to that host computer which means,
Your server is located at a distance from your home network. By using Remote Login, you can access your server at a distance and give it commands like shut down, new user, data add, data delete, etc. this can be securely done by SSH.
My server is in Delhi and m in Mumbai I want to access Delhi server trough remote ssh protocol can make you access Provides security on an unsecured channel.
Now you might get a question that SSh sounds very much like VPN, so what’s the difference. Here it is-
Difference between SSH and VPN
The main difference between these 2 technologies is that SSH connects to a particular computer while a VPN connects to a network.
VPN or Virtual Private network works on transport level whereas SSh works on application level.
VPN routes your all network traffics via a secure tunnel, whereas in SSH, you need to manually configure encryption to the software you need to be secured.
SSH encrypts data using 2 keys cryptography.
Also Read: SSH VS SSL
The key encrypts the data is public, whereas the key used to decrypt the data is a secret key, which makes SSH a very secure way of transferring data over the server.
What is SSH port?
SSh port number is 22, which holds a long story with it.
According to the writer of secure shell (SSH),
In spring 1995, the initial version of the secure shell was written. At that time, FTP and TElnet were ruling the networks. Telnet has port 23, and FTP has port 21, so technically port 22 was available. Also, it was between ports for Telnet and FTP.
He thought to have that port number was essential for gaining credibility. The necessary process for port allocation was relatively pure at that time.
Port numbers were allocated by Internet Assigned Numbers Authority(IANA). Back then, that meant an esteemed Internet pioneer called Jon Postel and Joyce K. Reynolds. He wrote an mail to IANA, and the very next day got a revert which has written on it,” We have assigned port number 22 to SSH, with you as the point of contact“.
By default, the SSH server still operates in port 22.
The number of the port can be configured by just changing the Port 22 directive in /etc/ssh/sshd_config. Also, it can be specified using the -p <port> option to sshd. The SSH client and sftp programs also support the -p <port> option.
Usage of SSH (What is SSH and It’s Use)
Apart from Remote Login, Secure Shell serves many other purposes such as:
- It is used for setting automatic (passwordless) login to a remote server
- It can be used for browsing the web through an encrypted proxy connection with SSH clients.
- It is used for development on a mobile or embedded device that supports SSH.
- It is used for securing file transfer protocols.
- It is also used for tunnelling a port.
- It is also used as a full-fledged encrypted VPN.
A secure shell ensures that whatever data you are sending via a server is safe and cannot be misused. So if you use a public network and you are worried about the safety of your data, then Secure Shell is there for you.
In this era, we need to be careful about the data we transfer because there are people in the middle who are ready to misuse your data for their profit.
If technology brought this insecurity, then technology is also offering us the solution. So let’s use it and be safe.
Keep your Data safe as the world runs on data.