Encrypted SIP calls and free OpenVPN access
DID Logic provides free options to secure your SIP calls. When you make SIP calls, voice data travelling over the Internet is sent as completely open packet stream. Anyone having access to the underlying network can listen in on your conversations without any special hardware or rocket science skills. Public WiFi, hotel Internet and shared computers are very vulnerable to this type of attack, however, almost any corporate IP network can be compromised as well. DID Logic provides free encryption tools to protect your sensitive conversations.
99% of all SIP providers send your calls unencrypted
Only a tiny fraction of VoIP providers offers SIP encryption and this is rarely enabled on the SIP provider side. When you make calls from that "Another-Cheap-Provider-Clone" application or use SIP trunking over public Internet, your voice conversation is sent as RTP stream of data that is not encrypted or protected in any way. In corporate IT environments, this is potentially a serious security threat and is unacceptable for business VoIP service today. Do you have a VoIP system installed in your organization? Ask your SIP provider if they encrypt the call traffic. They do not. Only a few providers send your VoIP calls over their own private IP backbone, however, that traffic is still not encrypted. While this is a standard way of sending SIP calls and the lack of encryption is not an issue for individual users, what you may not realize is the magnitude of the risk it poses to your corporate security.
Think your Skype calls are encrypted and unmonitored? Think twice.
While there has been no official proof of Skype having a backdoor, many sources, including high-ranking government officials in Italy and other EU nations, made references to listening in on Skype conversations . Of course, Skype has denied all claims of having keys to decrypt calls or sessions. Kurt Sauer, head of the security division of Skype, replied evasively: "We provide a secure means of communication. I will not say if we are listening in or not.". In China, text is filtered according to government requirements. This suggests that Skype has the capacity to eavesdrop on connections . Similar unconfirmed reports surfaced regarding other countries like Russia and Kazakhstan where government security agencies may have considered seeking agreements to obtain access to Skype conversation data . Microsoft has purchased Skype for $USD 8.5 billion. Will Microsoft enter into direct confrontation with the government agencies? Unlikely.
DID Logic offers free encrypted RTP service that is 100% secure
The Secure Real-time Transport Protocol provides encryption and message authentication and replay protection of the RTP data in unicast and multicast applications, including SIP voice transport. When any of your voice traffic is running over unreliable network with possible loss of packets, the standard encryption protocol - AES - is used with the encryption algorithm. AES (Advanced Encryption Standard) can have key sizes of up to 256 bits. With the computer technology presently available to humankind, it is currently impossible to decrypt SRTP voice traffic in real-time and listen in on your conversations. DID Logic does not have access to keys generated by user devices and we have no ability to intercept your encrypted calls data. Skype will not tell you if they can or cannot listen.2
Free OpenVPN service (VoiceVPN)
When you make unencrypted SIP calls over any network, all of your data can be potentially intercepted. DID Logic provides SIP over OpenVPN service to protect your conversations. OpenVPN is a free and open source software that creates a secure point-to-point connection by implementing virtual private network (VPN) technology. It can traverse NAT and firewall and eliminate your NAT-related SIP issues. It is accessible even if your ISP blocks specific VPN protocols. It is also cross-platform and you can use it on Windows, Mac, Linux or even install on a Linksys router so that all of your SIP devices can use secure VPN acccess and bypass any government or ISP blocks.
 Source: ZDnet blog - zdnet.com/blog/security/speculation-over-possible-skype-backdoor/1549
 Source: The Register - theregister.co.uk/2008/07/25/skype_backdoor_rumours/
 From Wikipedia article on Skype security en.wikipedia.org/wiki/Skype_security
OpenVPN and SRTP/zRTP access are free with certain minimum monthly spend levels (depending on your geographical region). Disclamer: Facts, statements made by other persons or companies, and any other information related to Skype® service are reproduced from publicly available sources including Wikipedia and The Register. DID Logic Ltd. makes no claims related to the nature of encryption, privacy principles, or other policies that Skype and Microsoft Corp. may or may not enforce on their networks and found in their proprietary software products that may or may not be associated with the Skype® service. DID Logic Ltd. does not have access to any information related to security features of Skype® service. This article is not intended to provide any advise or express any opinions regarding the Skype® service and only makes references to articles found on other publicly available Internet sites. Any interpretation of facts found on these other websites does not express the views of DID Logic Ltd. or its employees.