US 5,633,933 A · Method and apparatus for a key-management scheme for internet protocols

Abstract

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 .alpha..sup.i mod p. Node J is provided with a secret value j, and a public value .alpha..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 .alpha..sup.j mod p from the DH certificate. Node I then computes the value of .alpha..sup.ij mod p, and derives a key K.sub.ij from the value .alpha..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 .alpha..sup.i mod p. Node I then computes the value of .alpha..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.

Claims23

Dependent claims

In a computer network, a method for securely transmitting messages from a first node I to a second node J, said method comprising the steps of:

providing a first secret value i to node I;
keeping said first secret value i secret from nodes on said computer network other than I;
providing a second secret value j to node J;
keeping said second secret value j secret from nodes on said computer network other than J;
computing a first public value P.sub.i using as input said secret value i;
computing a second public value P.sub.j using as input said secret value j;
computing an implicit shared secret value SS, using as input said secret value i and said public value P.sub.j ;
deriving a key K.sub.1 from said implicit shared secret value SS;
generating a second key K.sub.2 ;
encrypting said second key K.sub.2 with said key K.sub.1 ;
encrypting said message with said second key K.sub.2 ;
sending said encrypted second key K.sub.2 and said encrypted message from node I to node J;
and
computing said implicit shared secret value SS, using as input said secret value j and said public value P.sub.i.

11 more elements

A method for securely transmitting a message from a first node N to a plurality of other nodes on a computer network, said method comprising the steps of:

providing a first secret value n to node N;
providing a second secret value m;
computing a first public value P.sub.n using as input said first secret value n;
computing a second public value P.sub.m using as input said second secret value m;
securely distributing said second secret value m to said plurality of other nodes;
computing an implicit shared secret value SS, using as input said first secret value n and said second public value P.sub.m ;
deriving a first key K.sub.1 from said implicit shared secret value SS;
generating a second key K.sub.2 ;
encrypting said second key K.sub.2 with said first key K.sub.1 ;
encrypting a message with said second key K.sub.2 ;
multicasting said encrypted second key K.sub.2 and said encrypted message from node N to said plurality of other nodes;
and
computing said implicit shared secret value SS, using as input said second secret value m and said first public value P.sub.n.

10 more elements

A computer program product comprising a computer usable medium having computer readable code embodied therein for securely transmitting messages from a first node I in a computer network to a second node J in said computer network, said computer usable medium comprising:

a computer readable program code device configured to provide a first secret value n to said node N;
a computer readable program code device configured to provide a second secret value m;
a computer readable program code device configured to compute a first public value P.sub.n using as input said first secret value n;
a computer readable program code device configured to compute a second public value P.sub.m using as input said second secret value m;
a computer readable program code device configured to securely distribute said second secret value m to said plurality of other nodes;
a computer readable program code device configured to compute an implicit shared secret value SS, using as input said first secret value n and said second public value P.sub.m ;
a computer readable program code device configured to derive a first key K.sub.1 from said implicit shared secret value SS;
a computer readable program code device configured to generate a second key K.sub.2 ;
a computer readable program code device configured to encrypt said second key K.sub.2 with said first key K.sub.1 ;
a computer readable program code device configured to encrypt a message with said second key K.sub.2 ;
a computer readable program code device configured to multicast said encrypted second key K.sub.2 and said encrypted message from node N to said plurality of other nodes;
and
a computer readable program code device configured to compute said implicit shared secret value SS, using as input said second secret value m and said first public value P.sub.n.

10 more elements

A computer program product comprising a computer usable medium having computer readable code embodied therein for securely transmitting a message from a first node N to a plurality of other nodes on a computer network, said computer usable medium comprising:

a computer readable program code device configured to provide a first secret value n;
a computer readable program code device configured to provide a second secret value m;
a computer readable program code device configured to compute a first public value P.sub.n using as input said first secret value n;
a computer readable program code device configured to compute a second public value P.sub.m using as input said second secret value m;
a computer readable program code device configured to securely distribute said second secret value m to said plurality of other nodes;
a computer readable program code device configured to compute an implicit shared secret value SS, using as input said first secret value n and said second public value P.sub.m ;
a computer readable program code device configured to derive a first key K.sub.1 from said implicit shared secret value SS;
a computer readable program code device configured to generate a second key K.sub.2 ;
a computer readable program code device configured to encrypt said second key K.sub.2 with said first key K.sub.1 ;
a computer readable program code device configured to encrypt a message with said second key K.sub.2 ;
a computer readable program code device configured to multicast said encrypted second key K.sub.2 and said encrypted message from node N to said plurality of other nodes;
and
a computer readable program code device configured to compute said implicit shared secret value SS, using as input said second secret value m and said first public value P.sub.n.

10 more elements

Dependencies are inferred from the claim text.

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

Life of this patent

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

Life of this patent

Abstract

Claims23