private communication

See: secret
References in classic literature ?
While these few words were being exchanged among the elders, a private communication was in course of progress between the two young people under the cabin table.
You say Gavrila Ardalionovitch has private communications with Aglaya?
Nay, he went farther, and in private communications with his Major would caution and rally him, crying, "Mind your oi, Dob, my boy, them girls is bent on mischief--me Lady has just got a box of gowns from Europe, and there's a pink satin for Glorvina, which will finish ye, Dob, if it's in the power of woman or satin to move ye.
She may have had, like myself, her own private communications for some favoured ear.
com)-- Private Communications Corporation, makers of Private WiFi, a new and innovative product in the security software market, today announced it has joined mediabistro.
Security technology company Private Communications Corporation (PCC) revealed today that it has formed a partnership with the Identity Theft Resource Center (ITRC) with the aim of bringing greater attention to security threats that occur over unencrypted WiFi networks.
The network enables a wide range of private communications services including wide area LANs, hosted thin-client server applications, storage area networking, and IP streaming of broadcast TV content, as well as Internet access at speeds starting at 100 million bits per second.
com)-- According to software company, Private Communications Corporation (PCC), "hackers can't steal what hackers can't see.