Patent ID: 7864770

Claim:
In a nested Virtual Private Network (VPN) system having at least one plaintext (PTX) domain, a ciphertext(CTX) domain, and at least one VPN router connected to the PTX domain and the CTX domain, the PTX domain having an IP address and the CTX domain having an IP address, the at least one VPN router having a CTX component and a PTX component with an IP address having a prefix of the IP address of the PTX domain and a host address of the VPN router, a method for generating an IP address of the CTX component using the IP address of the PTX domain for routing a packet in the VPN system, the method comprising: generating a hashed value of the prefix of the IP address of the PTX domain; providing the hashed value of the prefix to the CTX component of the VPN router; and generating the IP address of the CTX component with a prefix part and a host part, the prefix part represents a prefix of the CTX domain and the host part representing the hashed value of the prefix of the IP address of the PTX domain.