Updating and distributing encryption keys

Abstract

The present invention relates to methods for updating and distributing encryption keys. System and method for providing secure communications is provided. Initially, an exchange protocol, such as a password-authenticated key exchange protocol, is used to create a shared secret. From the shared secret, two keys are created: a utilized key and a stored key. The utilized key is used to encrypt messages between nodes. When it is time to replace the utilized key to maintain security, the stored key is utilized to encrypt messages for generating / distributing a new shared secret. The new shared secret is then used to generate a new utilized key and a new stored key. This process may be repeated any number of times to maintain security.

Description

technical field [0001] The present invention relates generally to systems and methods for providing security to communication networks, and more particularly to systems and methods for generating and distributing encryption keys. Background technique [0002] In order to provide confidentiality to communications between nodes of a network, it is known to provide encryption for messages. In general, it is best to provide each pair of communicating nodes with a different encryption key so that messages communicated in such a pair are specific to that pair. In this way, the third node cannot decipher and know the communication, even if it is exposed to the message (as would normally happen in a network running on a shared medium). [0003] However, an encryption key must be provided to each pair of nodes before it can be used to encrypt communications. It is most important to provide the encryption key to the communicating nodes in a secure manner, because if a third node lea...

AI Technical Summary

Problems solved by technology

[0004] Therefore, the first problem with providing secure communication between two nodes is the ability to pass secret information (such as encryption keys) on a shared medium without making it available to other nodes, which secret information enables Encryption between two nodes

[0005] The second problem is that even if a secret is passed between nodes without being compromised, encrypting a message with a secret over time will allow a third node to obtain that secret, allowing the third node to intercept and decrypt future messages. communication

A third node will not be able to learn the dual key from simply observing the exchange, even though it is not encrypted

However, if the PAK exchange is not used, but only a Diffie-Hellman exchange that is not password protected, there is a risk that node C acts as a MitM

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