Techniques for authenticating the identity of a caller in a telephone call are disclosed. The device generating the call implements encrypting caller identification information and initiating the telephone call, said initiating comprising providing a voice carrier signal including the caller identification information; and simultaneously providing a data carrier signal including the encrypted caller identification information. The receiving device implements receiving the telephone call; decrypting the encrypted caller identification information at the recipient device; and verifying the identity of at least an unknown caller at the recipient device by at least one of verifying the authenticity of a certificate used to encrypt the caller identification information; and comparing the decrypted caller identification information with the caller identification information from the voice carrier signal. A telephony device implementing such an authentication technique is also disclosed.