and 122 and a telephone 113 and 123 the cable modem 111 or 121 and the broadband telephone interface 112 or 122 may be separate or integral in a single box such as a broadband residential gateway brg and may further include a television interface likewise the cm 111 or 121 and or bti 112 or 122 may be included in the pc 114 or 124 the cpe 110 and 120 may further include a means for generating cryptographic keys such as cryptography software for example pretty good privacy pgp the means for generating cryptographic keys may be contained in any of the cpe 110 and 120 for example in the pc 114 and 124 or in the bti 112 and 122 further the means for generating cryptographic key may include both hardware and software or may reside somewhere else in the broadband communication system in any case the cryptographic keys may include both private and public keys and will provide electronic signature and verification means for certified mail the private key may be a first algorithm that encodes the voice mail or multimedia mail message and the public key may be a second algorithm related to the first algorithm that decodes the voice mail or multimedia mail message so that the original message can be recaptured from the signed message the internet broadband network 130 may include a plurality of cable modem termination systems cmts 131 and 132 to couple to the plurality of cable modems e g cms 111 and 121 coupled to the broadband communication system and one or more gate controllers 133 to coordinate communication traffic throughout the broadband system the internet broadband network 130 may be coupled to a pstn 160 via.