IPSec is an Efficient Security Enhancement to TCP/IP

TCP/IP has innate flaws. It was meant to run on a government network with a small number of hosts that trusted each other. Security was not a priority for the creators. However, now the network has been expanded worldwide, our most critical concern is security. Therefore, some extra measures were required to protect conversations via the Internet. In this blog, we will explain what Internet Protocol Security is and how it can offer protection over networks.

What is IPSec?

A variety of solutions have been developed by security developers to provide security to TCP/IP’s unsafe architecture. One of the most significant breakthroughs has been the introduction of IPSec, a security upgraded version of the Internet Protocol.

  • It is a collection of protocols for securely transmitting data across a public channel, such as the Internet. IPSec is not limited to a single authentication method or algorithm. This is known as an “open standard.”
  • IPSec is applied at the network layer.

IPSec can also be implemented in two separate modes of operation:

Transport Mode

IPSec in transport mode requires just the data (or payload) to be encrypted during transit. The benefit of this is that the packets are smaller since the IP headers are not encrypted.

The disadvantage of the transport mode is that a hacker may sniff the network and collect information about end-users. You can use transport mode IPSec in host-to-host VPNs.

Tunneling Mode

Tunnel mode encrypts the payload and the headers. The benefit is that neither the payload nor the header information needs to be sniffed. The drawback is speed. As the size of the encrypted packet grows, speed becomes an issue.

You can utilize tunnel mode IPSec, used in VPNs that connect hosts to gateways or gateways to hosts.

IPSec protocols

IPSec is composed of two distinct security protocols.

The authentication header (AH)

  • The authentication header protocol is in charge of ensuring the authenticity and integrity of the payload.
  • AH validates packets via signature, which ensures data integrity. The signing is special to the data being broadcast, ensuring its authenticity and integrity.

The encapsulating security payload (ESP)

  • The encapsulating security payload protocol likewise manages payload authenticity and integrity, but it also provides the benefit of data secrecy via encryption.
  • AH, and ESP can be utilized in conjunction or independently.
  • When used in conjunction, the entire packet is authenticated.

What is a security association (SA)?

A security association is a contract that specifies how single or multiple organizations will use security services to communicate safely.

Authentication using IPSec

To protect the integrity of data carried through IPSec, a process for authenticating end users and managing secret keys must be used. This system is noted as the Internet Key Exchange.

  • Before IPSec communications begin, IKE verifies the identities of the two endpoints by allowing a swap of a mutual key safely.
  • Both sides exchange a hashed version of a pre-shared key during IKE discussions.
  • They attempt to reconstruct the hashed data after receiving it.
  • Both parties can commence encrypted conversations if they correctly reproduce the hash.

While public-key cryptography can be utilized in IPSec, it does not provide non-repudiation. The most important factor to consider when choosing an authentication strategy is that both parties must agree on the approach.

  • A SA is used by IPSec to indicate how parties will interact using the authentication header protocol and encapsulating the security payload.
  • The security association can be created manually or through the use of the Internet Security Association and Key Management Protocol (which is abbreviated as ISAKMP).


You must ensure confidentiality, validity, integrity, and security for network activity. IPSec is an efficient security enhancement to TCP/IP. Along with its two special security protocols, IPSec seems to provide numerous levels of protection to the communication process.

Do you want to get practical skills to work in cybersecurity or advance your career? Enrol in MCSI Bootcamps!