Important: Your current Windows version is outdated and no longer supported.
For your security, we recommend switching to Windows 10 or Windows 11 before downloading Avira software. Update your Windows version here.
Our Avira Phantom VPN is no longer available for use within India as a result of governmental regulations requiring the logging and saving of user data, but you can still use your subscription when traveling outside of India.
Skip to Main Content
  1. Home
  2. Security Wordbook
  3. IPsec

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 The other is called Transport Layer Security (TLS), and it is a newer version of the old Secure Sockets Layer (SSL).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?

Download Avira Phantom VPN for free Download Avira Phantom VPN for free Download Avira Phantom VPN for free Download Avira Phantom VPN for free
< Previous item Next item >
Automatically renews, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Automatically renews, unless the renewal is cancelled. Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer for the 1st #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer for the first #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer for the 1st #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the first 2 year price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the first 2 year price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Subscription details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / first #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period# (#cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#), and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / first #cma_period# (#cma_promo_saved_price# off the first 2 year price of #cma_promo_standard_price#), and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period# (#cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#), and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. Special offer for the 1st #cma_period# until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. Special offer for the first #cma_period# until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / first #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. Special offer for the 1st #cma_period# until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. Special offer until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period# (#cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#), and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. Special offer until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / first #cma_period# (#cma_promo_saved_price# off the first 2 year price of #cma_promo_standard_price#), and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Payment method required. Special offer until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period# (#cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#), and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Price subject to change.
Offer details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Savings compared to the renewal price. Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Savings compared to 2 x annual renewal price of #cma_promo_renewal_price# / year. Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Savings compared to the renewal price. Subscription details below.*
Special offer for the 1st #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Subscription details below.*
Special offer for the first #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Subscription details below.*
Special offer for the 1st #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Savings compared to the renewal price. Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the first 2 year price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Savings compared to 2 x annual renewal price of #cma_promo_renewal_price# / year. Subscription details below.*
Special offer until #cma_promo_end_date#: #cma_promo_price# — #cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Savings compared to the renewal price. Subscription details below.*
Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Savings compared to the renewal price. Subscription details below.*
Special offer for the 1st #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Subscription details below.*
Special offer for the first #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Subscription details below.*
Special offer for the 1st #cma_period# until #cma_promo_end_date#. Automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Subscription details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / first #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / first #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. Special offer for the 1st #cma_period# until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period# and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. Special offer for the first #cma_period# until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / first #cma_period# and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. Special offer for the 1st #cma_period# until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period# and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. Special offer until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. Special offer until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / first #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. Special offer until #cma_promo_end_date#. When trial ends: paid subscription starts at #cma_promo_price# / 1st #cma_period#, and automatically renews at #cma_promo_renewal_price# / #cma_renewal_period#, unless the renewal is cancelled. Offer details below.*
Payment method required. When trial ends: paid subscription starts and automatically renews, unless the renewal is cancelled. Price subject to change.
Offer details below.*
#cma_promo_price# — #cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#. Then #cma_promo_renewal_price# / #cma_renewal_period#.
#cma_promo_price# — #cma_promo_saved_price# off the first 2 year price of #cma_promo_standard_price#. Then #cma_promo_renewal_price# / #cma_renewal_period#.
#cma_promo_price# — #cma_promo_saved_price# off the 1st #cma_period# price of #cma_promo_standard_price#. Then #cma_promo_renewal_price# / #cma_renewal_period#.
The remaining value left on your current subscription is converted into additional days in your new subscription.
Big savings. Strong online security: 45% off Avira Prime >
Riesen Rabatt. Starke Online-Sicherheit: 45% auf Avira Prime >