Method and apparatus for dynamic, seamless security in communication protocols
View Patent ↗Communication nodes, acting as intermediate routers for communication packets transmitted between a source node and a destination node, are provided with different access rights to the fields of the routed communication packets. Routes of intermediate routers between the source node and the destination node are discovered and the identities of intermediate routers on the discovered routes are collected. The aggregate trust levels of the intermediate routers are computed allowing the most trusted route to be selected. Encryption keys are securely distributed to intermediate routers on the most trusted route based on the trust level of the intermediate routers and fields of the communication packets are encrypted with encryption keys corresponding to the assigned trust level. Intermediated nodes are thereby prevented from accessing selected fields of the communication packets.
1. A method for secure routing of a communication packet from a source node of a network to a destination node, comprising:
distributing a first public encryption key corresponding to a first private encryption key of the source node to a first intermediate router of the network and to the destination node;
distributing a second public encryption key corresponding to a second private encryption key of the source node to the destination node but not to the first intermediate router;
encrypting data of the communication packet using the first private key and a second private key of the source node;
encrypting a header of the communication packet using the first private key of the source node but not the second private encryption key, the header including routing information;
transmitting the communication packet to the first intermediate router;
the first intermediate router decrypting the header using the first public key to recover the routing information;
the first intermediate router transmitting the communication packet to the destination node in accordance with the routing information; and
the destination node decrypting the data using the first public key and second public key.
2. The method in accordance with claim 1 , wherein the first intermediate router transmitting the communication packet to the destination node in accordance with the routing information comprises intermediate router transmitting the communication packet to the destination node via at least one second intermediate router.
3. The method in accordance with claim 1 , wherein a plurality of intermediate nodes with different access rights to fields of the communication packet is disposed between the source node and the destination node, and the method further comprises:
discovering routes of the intermediate routers;
collecting the identities of the intermediate routers on the discovered routes;
computing aggregate trust levels of the intermediate routers along the discovered routes;
selecting a most trusted route of the discovered routes;
computing and securely distributing encryption keys to intermediate routers on the most trusted route based on the trust level of each intermediate router; and
encrypting fields of the communication packet with corresponding encryption keys.
4. The method in accordance with claim 3 , further comprising the source node and the destination node authenticating with each other.
5. The method in accordance with claim 4 , further comprising authenticating the intermediate routers on the most trusted route to the source and destination nodes.
6. The method in accordance with claim 3 , further comprising redistributing encryption keys based on behavior of the intermediate routers on the most trusted route.
7. The method in accordance with claim 3 , wherein collecting identities of intermediate routers on the discovered routes comprises adding public key certificates of the intermediate routers to messages sent from the intermediate routers.
8. The method in accordance with claim 3 , wherein computing the aggregate trust levels of the intermediate routers comprises selecting a minimum value of the trust levels of the intermediate routers along a particular route assessed by the source node and the destination node.
9. The method in accordance with claim 3 , wherein selecting the most trusted route of the discovered routes comprises the source node selecting among all the discovered routes the route with the most trusted weakest intermediate router.
10. The method in accordance with claim 3 , further comprising the source node generating encryption keys for each field of the communication packet.
11. The method in accordance with claim 3 , wherein securely distributing encryption keys to intermediate routers on the most trusted route comprises the source node encrypting a particular key with a public key of the intermediate router and signing the encrypted particular key with the private key of the source node.
12. The method in accordance with claim 3 , wherein computing the encryption keys is performed by the source node.
13. The method in accordance with claim 3 , further comprising if malicious behavior is detected in a particular intermediate router on the most trusted route:
reducing the trust level of the particular intermediate router;
updating the aggregate trust levels of the discovered routes;
selecting a new most trusted route based on the updated aggregate trust levels of the discovered routes; and
distributing new encryption keys to the intermediate routers on the new most trusted route in accordance with the reduced trust level of the particular intermediate router.
14. The method in accordance with claim 3 , further comprising if cooperative behavior of the intermediate routers is detected in a particular intermediate router:
increasing the trust level of the particular intermediate router;
updating the aggregate trust levels of the discovered routes;
selecting a new most trusted route based on the updated aggregate trust levels of the discovered routes; and
distributing new encryption keys to the intermediate routers on the new most trusted route in accordance with the increased trust level of the particular intermediate router.
15. The method in accordance with claim 3 , wherein securely distributing the encryption keys comprises providing a different number of encryption keys to the intermediate routers on the most trusted route based on the trust level of each intermediate router.
16. The method in accordance with claim 15 , wherein the communication packet comprises a plurality of headers in addition to a data payload, and encrypting fields of the communication packets comprise encrypting each header using a different encryption key and encrypting the data payload using an encryption key that is different from the encryption key used for encrypting any of the headers.
17. The method in accordance with claim 1 , further comprising:
transmitting a KEY_REQUEST message from the first intermediate router to the source node, the KEY_REQUEST message comprising:
a Key Usage identifier specifying a security procedure for which a key request is made;
an identifier of the first intermediate router;
an identifier of the source node; and
a public key of the first intermediate router; and
wherein distributing the first public encryption key to the first intermediate router comprises transmitting a KEY_RESPONSE message from the source node to the first intermediate router in response to the KEY_REQUEST message, the KEY_RESPONSE message comprising:
a Trust Level specifying a trust level granted to the first intermediate router by the source node; and
a security key corresponding to and in a different field from the Trust Level.