Assuming an organisation has 2 offices at two different locations and needs secure communication between them. As far as I understand IPSec, we can use tunnel mode to provide end to end encryption for the data transported from each location. But how is it more secure or why should we prefer it over the transport mode for given scenario? Also how does it make it secure transmission? Also ignore my stupidity but is IPSec only possible to implement when creating a VPN or is it something that is seen more often like when we use WhatsApp or some other service?
2 Answers
But how is it more secure or why should we prefer it over the transport mode for given scenario?
When using ESP, both tunnel and transport mode encrypt the payload. Tunnel mode also encrypts the addresses of the hosts, while transport does not. In addition, tunnel mode allows you to "hide" all the internal addresses, while transport mode requires that you expose them to the unprotected network.
Also how does it make it secure transmission?
Again, using the ESP header, the payload is encrypted
Also ignore my stupidity but is IPSec only possible to implement when creating a VPN or is it something that is seen more often like when we use WhatsApp or some other service?
You can use IPsec with any IP unicast protocol. There are other ways to encrypt data at the application layer, such as TLS, but application layer protocols are off topic here.
But how is it more secure or why should we prefer it over the transport mode for given scenario?
Configure correctly, IPsec provides a secure tunnel link. Any packets passed on that link are securely encrypted, no matter what they contain.
Also how does it make it secure transmission?
Packets inside the tunnel are encrypted and encapsulated in ESP packets, preventing unauthorized eavesdropping or manipulation.
is IPSec only possible to implement when creating a VPN or is it something that is seen more often like when we use WhatsApp or some other service?
IPsec is designed for and predominantly used with VPN. It isn't used with applications directly, but it can be used to secure access to otherwise unsecured applications (with a VPN). The two most common scenarios for VPN are site-to-site tunneled links between locations and remote client access to private networks.
The usual way to secure applications directly is with the use of transport layer security (TLS) which most applications support.
