In accordance with an embodiment of the present invention, a client device includes a biometric unit, a transceiver unit, and a cryptographic engine. The biometric unit generates a first biometric feature at a first time and a second biometric feature at a second time based on sensing a portion of a human body. The transceiver unit sends and receives message data over a network. The cryptographic engine encrypts and decrypts message data, generates client public and private keys associated with a client device identifier, and generates biometric public and private keys associated with the first user biometric feature. The cryptographic engine encrypts a hash of a first message data using the biometric private key when the first and second biometric features match, and appends the encrypted hash forming an authenticated first message data that is encrypted by a server public key and sent over the network.