What is a VPN?

When data transmitted over the Internet uses a public network infrastructure, the path they follow is not defined in advance. It is then possible that the network is “listened”, worse, that the traffic is diverted by an indiscreet user.

The need for secure communication is therefore essential for the exchange of sensitive information. However, most companies can not afford to link their local networks with dedicated links; it would be excessively expensive.

Instead, the Internet is used as a public, insecure and unreliable network. How can one then transit his confidential information in this condition without being intercepted? This is the problem that responds to the VPN Virtual Private Network or VPN, the acronym for Virtual Private Network.

VPN is, therefore, an excellent compromise that, taking the internet as a transmission medium, uses an encapsulation protocol (in English tunneling) to transmit the data in a secure way.

A VPN for end-to-end security

VPN is called virtual network because it connects two physical networks (local area networks) over the Internet which is an unreliable virtual link. It is said to be private because only computers on these local networks can access the data.

It will be remembered that the VPN makes it possible to obtain a secure link for the exchange of data.

How does a VPN work?

Two main elements are used when establishing a secure VPN link between two hosts. The typical scenario being the access to data of an organization by a third party user from a remote location, these elements are:

A VPN server whose role is to encrypt and decrypt data on the enterprise side
A VPN client whose role is to encrypt and decrypt data on the remote user’s side.

When the user wants to access the virtual private network, his request is transmitted to the gateway system. The latter will connect to the remote network via a public network infrastructure and then transmit the request encrypted.

The remote computer will then provide the data to the VPN server of its local network that will transmit the response in an encrypted manner. Upon receipt on the user’s VPN client, the data will be decrypted for readability

Data encapsulation

The operation of the VPN is also based on the encapsulation or tunneling protocol used. It is a protocol that, thanks to some cryptography algorithms, helps protect the data that pass through the VPN.

The main tunneling protocols frequently used by VPNs are Point-To-Point Tunneling Protocol (PPTP), Layer-to-Forwarding (L2F), Layer-to-Tunneling Protocol (L2TP), IPsec and OpenVPN.

At the entrance and exit of the VPN, the data is encrypted using these protocols. Anyone who tries to intercept the traffic will end up with incomprehensible and almost indecipherable data.

Why buy a VPN?

The reasons that support the purchase of a VPN in 2018 are legion. First of all, the VPN offers the possibility of securing the user’s internet connection. Thanks to it, the client has the possibility to encrypt all the packets that he sends or receives through the VPN tunnel.

The various risks of espionage, loss or interception of data are thus greatly reduced. In addition, the use of the VPN also allows the user to surf the net anonymously. He may use a (virtual) IP address other than his own to circumvent various forms of unwanted surveillance on the internet.

No trace of the activities performed through a virtual private network is then identifiable. On the other hand, the VPN makes it possible to circumvent censorship and geo-restrictionn on the internet. Whether to impose traditional social values, to maintain political stability or national security, censorship and restrictions have often placed limitations on the use of the Internet.

Fortunately, VPNs have evolved and now allow to easily bypass this category of restrictions through the use of non-blacklisted IP addresses. And finally, the VPN can stream from any location, even download content without risk.


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