IPsec, also known as the internet Protocol （1） ,defines the architecture for security services for IP network traffic IPsec describes the framework for providing security at the IP layer, as well as the suite of protocols designed to provide that security: through （2） and encryption of IP network packets. IPsec can be used protect network data, for example, by setting up circuits using IPsec （3）,?in which all data being sent between two endpoints is encrypted, as?with a Virtual （4） Network connection;for encrypting application layer data;and for providing security for routers sending routing data across?the public internet. Internet traffic can also be secured from host to host without?the use of IPsec, for example by encryption at the （5） layer with HTTP Secure (TTPS)or an the transport layer with the Transport ?Layer Security (TLS)protocol.

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