TransNexus and Emergent Network Solutions on Monday certified the Entice Session Border Controller and NexSRS certificate authority and settlement server which are now fully interoperable for secure VoIP peering.   The system combo uses Public Key Infrastructure (PKI) services for a more secure peer to peer access control and settlement accounting among interconnect peers. This security feature allows VoIP wholesalers, VoIP clearinghouses, IP transport providers and network co-location providers to "increase customer loyalty and generate new revenues from peer to peer VoIP traffic," noted the companies` news release.   Secure VoIP peering for Entice now includes two new features used to reduce interconnect fraud risk and settlement disputes. "First, digitally signed tokens included with each call setup ensure secure peer to peer access control. Second, real time collection of encrypted call detail records from both source and destination peers eliminate interconnect settlement billing disputes," explained the release.