US Patent 7908482 Key confirmed authenticated key exchange with derived ephemeral keys

Key confirmed (KC) authenticated key exchange (AKE) with derived ephemeral keys protocol using a mathematical group is described. In one aspect, a first party, using the mathematical group, determines whether a second party has received information to compute an agreed session key value for exchanging information securely with the first party. At least a subset of the received information is computed using derived ephemeral keys of the first and second parties. The first party generates the agreed session key value only when the second party has demonstrated receipt of the information.