What is IPsec?
Security at the IP level
IPsec (Internet Protocol Security) is a network protocol that encrypts and authenticates data at the IP layer, regardless of the type of applications being transmitted. It is used to establish secure connections over unsecured networks such as the internet. IPsec protects data through encryption, integrity checks and authentication, enabling the establishment of trustworthy communication channels. As remote work becomes standard and in an era of multi-cloud infrastructures and growing cyber risks, IPsec is used as an additional security technology alongside TLS/HTTPS for client-site VPNs. IPsec is also finding its way into the private sphere, for example, to secure private communication over public hotspots (TLS interception) or to access regionally restricted services.
Secure data connections across locations
IPsec underpins many VPN solutions by protecting IP packets from unauthorized access, making it ideal for secure communication over the internet.
IPsec doesn’t just encrypt content – it builds trust between network participants across insecure connections.
IPsec’s flexibility makes it suitable for complex architectures
IPsec operates independently of applications and ports, making it a robust option for securing heterogeneous IT landscapes, cloud services or hybrid networks.
How IPsec works
IPsec provides confidentiality through encryption, authentication and integrity for IP packets. It uses Authentication Header (AH) and Encapsulating Security Payload (ESP) to protect data. Authentication and key exchange are typically handled via the Internet Key Exchange (IKE), which establishes secure sessions manually or automatically. IPsec runs in two modes: transport mode, where only payload data is encrypted and IP addresses are not changed, or tunnel mode, where complete IP packets are encapsulated and IP addresses are replaced with the addresses of the tunnel endpoints, for example, to secure site-to-site VPNs or for secure communication with mobile devices.
Future-ready and interoperable network security
Adva network security integrates IPsec and MACsec in one portfolio and centralizes provisioning, policy and key management.
Why IPsec matters for hybrid, cloud and zero-trust networks
IPsec is standardized, widely supported and manageable through APIs or centralized network tools. It enables the secure exchange of sensitive data over public networks – a central element of modern security strategies and is used to connect distributed locations, implement secure remote access or encrypt data traffic between clouds. Particularly for hybrid IT environments that use a wide variety of applications, platforms and providers, IPsec creates uniform, consistent security policies. Thanks to its flexibility and widespread use, it remains an indispensable tool in an era of zero trust.
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