Taking a SIP of secure mobile telephony
<<<... "We could improve the speed by moving to 128-bit encryption instead of 256-bit, but we don't want to do that," he said. Users may also need to ensure that their tariff permits VoIP, as some T-Mobile ones don't, for example - although as Francis points out, if the data is encrypted, how is the network going to identify it? A few other companies already offer secure VoIP to mobile handsets, for example earlier this year Allied Telesis (Allied Telesyn as-was) released a lightweight VPN for mobile devices, which also supports SIP-based telephony and includes 128-bit encryption. Allied's David Ward warned that voice-only encryption was the wrong way to go - instead, you should encrypt the whole data channel, he said. "My clients love IP telephony because they don't have to run a separate security network for voice, they just run it within the data envelope," he added. "It's narrow-band thinking to think only of voice - you need multiple modes of communication." There is also the possibility that Safe-Com has jumped the gun on VoIP security. The Internet Engineering Task Force has produced an RFC for Secure SIP, which should eventually lead to a standard. "We've got to have a common, standard, no-options protocol," said Kurt Jacobs, channel business development director at IP PBX developer Sphere Communications. He added that the problem is the load that encryption places on a smartphone's processor at a time when handset makers are trying to drive cost out of their phones.