Chapter 3 VPN Security Technology
Since the private information is transmitted, VPN users are more concerned about the security of the data.
At present, VPN mainly adopts four technologies to ensure security. These four technologies are Tunneling, Encryption & Decryption, Key Management, User and Device Authentication. ).
1. Tunneling technology:
Tunneling technology is the basic technology of VPN, which is similar to point-to-point connection technology. It establishes a data channel (tunnel) in the public network, and allows data packets to be transmitted through this tunnel. Tunnels are formed by tunneling protocols, which are divided into Layer 2 and Layer 3 tunneling protocols. The second layer of tunneling protocol is to first encapsulate various network protocols into PPP, and then encapsulate the entire data into the tunneling protocol. The data packets formed by this double-layer encapsulation method are transmitted by the second layer protocol. Layer 2 tunneling protocols include L2F, PPTP, and L2TP. The L2TP protocol is the current IETF standard, formed by the IETF merging PPTP and L2F.
The Layer 3 tunneling protocol is to directly load various network protocols into the tunneling protocol, and the formed data packets rely on the Layer 3 protocol for transmission. Layer 3 tunneling protocols include VTP, IPSec, and so on. IPSec (IP Security) is composed of a set of RFC documents, which define a system to provide security protocol selection, security algorithm, determine the key used by the service and other services, so as to provide security at the IP layer.
2. Encryption and decryption technology:
Encryption and decryption technology is a relatively mature technology in data communication, and VPN can directly use the existing technology.
3. Key management technology:
The main task of key management technology is how to securely transmit keys on the public data network without being stolen. The current key management technology is divided into SKIP and ISAKMP/OAKLEY two. SKIP mainly uses the Diffie-Hellman algorithm to transmit keys on the network; in ISAKMP, both parties have two keys, which are used for public and private use respectively.
4. User and device authentication technology:
The most commonly used user and device authentication technologies are user name and password or card authentication.
ps: reprint someone else's as a note for yourself