IPsec

What is IPsec?

Internet Protocol Security, or in short IPsec, is a group of network protocols used for authenticating and encrypting data transferred over public networks. The IPsec protocol suite is one of the two protocols used in VPNs. The other is called Transport Layer Security (TLS), and it is a newer version of the old Secure Sockets Layer (SSL). Although TSL is a newer standard, the two protocols have many similarities, so they are usually encountered in documentation as TLS/SSL.

While TSL/SSL protocols are using encryption to secure applications, IPsec was designed to secure networks. Initially, it was a requirement for IPv6 addresses, but the slow adoption of IPv6 made IPsec common also for IPv4 addresses. To find out more about IP addressed and the difference between IPv6 and IPv4, read our entry on IP.

How does IPsec work?

Data transmitted over the internet is split into multiple bits called packets. The content of the packet is called payload, and information about the packet, the meta-data, is called header. IPsec encrypts both the payload and the header for each package. Data packages are then transmitted through the network using a transport protocol, and once they arrive at the destination, they are decrypted. Encryption requires cryptographic keys and cryptographic algorithms. The keys transform plaintext (including bits) into ciphertext, and the algorithm provides the method for encrypting and decrypting data. When a sender and a receiver establish a connection, they first have to exchange keys. An IPsec connection is established in six steps:

1. Setting up the key exchange between devices

2. Adding headers and trailers to data packets

3. Providing authentication for data packets

4. Encrypting the data packets

5. Transmitting the data packets

6. Decrypting the data packets upon delivery

Avira Phantom VPN supports both IPsec and SSL/TSL protocols. For computers and laptops running Windows and macOS, as well as for Android devices, our VPN uses the SSL/TSL protocols based on the OpenVPN open-source software. For iOS devices and applications from the AppStore and Microsoft Store, Avira Phantom VPN is using the IPsec protocol.

Learn more about VPNs:

What is a VPN?

How to use a VPN for anonymous browsing?

How to bypass heo-restrictions with a VPN?