What Is IPsec (Internet Protocol Security)? How Does It Work?

What Is IPsec (Internet Protocol Security)?

What is IPsec? IPsec is short of Internet Protocol Security. As its name implies, “IP” stands for Internet protocol and “sec” stands for secure. IPsec is a set of protocols and algorithms used to set up VPNs, an encrypted connection between devices.

IPsec adds encryption and authentication to make the protocol more secure and encrypts sensitive information to prevent unwanted monitoring so that the server can also verify that the received data packets are authorized.

IPsec is the main routing protocol used on the Internet and these IPsec protocols are commonly used for VPNs to establish and run these encrypted connections. However, not all VPNs use IPsec some of them can use SSL or TLS.

How Does IPsec Work?

To establish IPsec connections, there are some steps included.

1. Once the computer initiates secure IPsec transmission with the recipient computer, IPsec will set up keys with a key exchange between the connected devices, so that each device can decrypt the other device’s messages.
2. When one computer sends the data to another device, the data will be divided into smaller pieces and then IPsec will add several headers containing authentication and encryption information. This ensures that packets are from a trusted source and not an attacker.
3. Encrypted IPsec packets travel across one or more networks to their destination using a transport protocol and at the other end of the communication, the packets are decrypted, and applications can now use the delivered data.

What Is IPsec Used for?

There are many uses of IPsec. Many organizations will use IPsec to protect against all kinds of cyber-attacks, especially replay attacks. Of course, as we mentioned, the most commonly used is IPsec VPN with its powerful features to secure your data, for example,

• It can protect network data by setting up encrypted circuits.
• It can encrypt application data.
• It can ensure router security when sending data across the public Internet.
• It can provide authentication without encryption.
• It can secure virtual private networks.

What Are the IPsec Protocols?

We have introduced that IPsec is not one protocol but a suite of protocols. Protocol, in networking, is used to format data and prepare information for network transmission.

Some IPsec protocols are given below.

Authentication Header (AH)

The AH protocol is used to verify if the data packets come from a trusted source or being tampered or not. In other words, it provides data origin authentication, data integrity, and replay protection.

Encapsulating security payload (ESP)

Encapsulating security payload is used to encrypt and authenticate the packets of data between computers using a Virtual Private Network (VPN). It encrypts the IP header and the payload for each packet and adds its own header and a trailer to each data packet.

Internet key exchange (IKE)

Internet key exchange (IKE) is a secure key management protocol that is used to set up a secure, authenticated communications channel between two devices.

Both devices set up security association (SA), which refers to a number of protocols used for negotiating encryption keys and algorithms, and Internet key exchange is one of the most common SA protocols.

What Are IPsec Modes?

To make the definition easy to learn, targeting one single session, transport mode will protect data from one device to another one. While IPsec operates in two different modes with different degrees of protection.

Tunnel mode

This mode can be applied for transferring data on public networks to protect the data form the unauthorized parties via encryption.

An IPsec tunnel is established between two gateway hosts, but the tunnel itself carries traffic from any host in the protected network.

Transport mode

Different from Tunnel mode, the transport mode encrypts only the data packet’s payload while the IP header will remain its original form. The unencrypted part allows router to identify the destination address of each data packet. Therefore, the transport mode can be a better choice when one host needs to interact with another host.

Bottom Line:

What is IPsec? IPsec is useful to enhance your cyber security and this article has given you much information about IPsec. If you have any other questions about IPsec, please leave your message.