Symmetric and asymmetric ciphers may be used to cryptographically secure communications over an insecure channel, as known in the art.
Frequently, a shared encryption key may need to be established over the insecure channel. Methods for key establishment include Diffie-Hellman key exchange, Simple Password Exponential Key Exchange (SPEKE) and the Burmester and Desmedt (BD) protocols, for example.
USPTO Backgrounds
USPTO Backgrounds