Method and apparatus for a key-management scheme for internet protocols

摘要

A first data processing device (node I) is coupled to a private network which is in turn coupled to the Internet. A second data processing device (node J) is coupled to the same, or to a different network, which is also coupled to the Internet, such that node I communicates to node J using the Internet protocol. Node I is provided with a secret value i, and a public value &agr;.sup.i mod p. Node J is provided with a secret value j, and a public value &agr;.sup.j mod p. Data packets (referred to as "datagrams") are encrypted using the teachings of the present invention to enhance network security. A source node I obtains a Diffie-Helman (DH) certificate for node J, (either from a local cache, from a directory service, or directly from node J), and obtains node J's public value &agr;.sup.j mod p from the DH certificate. Node I then computes the value of &agr;.sup.ij mod p, and derives a key K. sub.ij from the value &agr;.sup.ij mod p. A transient key K.sub.p is then generated at random, and K.sub.p is used to encrypt the datagram to be sent by node I. K.sub.p is then encrypted with key K.sub.ij. Upon receipt of the encrypted datagram by the receiving node J, the node J obtains a DH certificate for node I, (either from a local cache, from a directory service, or directly from node J), and obtains the public value &agr;.sup. i mod p. Node I then computes the value of &agr;.sup.ij mod p and derives the key K.sub.ij. Node J utilizes the key K.sub.ij to decrypt the transient key K.sub.p, and using the decrypted transient key K.sub.p, node J decrypts the datagram packet, thereby resulting in the original data in unencrypted form.