Based on the hypothesis that the velocity of light in vacuum is the maximum velocity possible for any signal, we present a dual velocity protocol for a hybrid quantum key distribution (QKD) system, and prove that its security is the same as that for the BB84 protocol.

The paper has discussed routing aspects of IPv6 transition,and introduced such techniques as dual stack application in dual-IP environment,point to point tunneling and NAT-PT based on ALG.

The thesis designs a IPv4/IPv6 dual stack firewall based on Linux,which chooses shield host system structure.

Focusing on dual stack technology, the operation of nodes with a dual IP layer-IPv4/IPv6 nodes is discussed too.

The transition mechanism of IPv6, the dual stacks tunnel technology, the translation technology and some practical tools for transition are specially expounded.

On the background of the embedded home gateway, the embedded Web Server which can support IPv4 and IPv6 dual stacks on the low speed CPU with limited resources has been studied.

The paper analysed the necessity of the IPv6 Web-building,the dual stack,the tunneling technology and NAT-PT technology commonly used in three transitional technologies,According to the local universities’ capital,technology and so on,the author put forword the strategy upgrading from the IPv6 test network to the Campus Network Stack IPv4/IPv6.

A phase modulated QKD system with two quantum cryptography protocols;