Patent ID: 9628450
Date: 2017-04-18
CPC Classifications: H04L

Claim:
1. A computer implemented method for voice and video data encryption and decryption without sharing a private key, in a distributed video conferencing system including a plurality of client terminals communicating data at different data rates, the method comprising: upon initiating a video conference amongst the plurality of client terminals, receiving by a second client terminal of the plurality of client terminals, a first public key from a first client terminal of the plurality of client terminals; generating a second/first key switch hint for the first client terminal, by the second client terminal, using the first public key and a second private key of the second client terminal; transmitting the second/first key switch hint and a second encrypted data from the second client terminal to a mixer; receiving by a fourth client terminal of the plurality of client terminals, a third public key from a third client terminal of the plurality of client terminals; generating a fourth/third key switch hint for the third client terminal, by the fourth client terminal, using the third public key and a fourth private key of the fourth client terminal; transmitting the fourth/third key switch hint and fourth encrypted data from the fourth client terminal to the mixer; receiving by the third client terminal, the first public key from the first client terminal; generating a third/first key switch hint for the first client terminal, by the third client terminal, using the first public key and a third private key of the third client terminal; transmitting the third/first key switch hint from the third client terminal to the mixer; using, by the mixer, the second/first key switch hint and the second encrypted data from the second client terminal to switch the second encrypted data to generate a first switched encrypted data; adding, by the mixer, the first switched encrypted data to the first encrypted data received from the first client terminal to output a first summed encrypted data; using, by the mixer, the fourth/third key switch hint and a third encrypted data from the third client terminal to switch the fourth encrypted data to generate a second switched encrypted data; adding, by the mixer, the second switched encrypted data to the third encrypted data received from the third client terminal to output a second summed encrypted data; using, by the mixer, the third/first key switch hint and the second summed encrypted data to switch the second summed encrypted data to generate a third switched encrypted data; adding, by the mixer, the third switched encrypted data to the first summed encrypted data to output a third summed encrypted data, wherein each encrypted data is encrypted voice or video data, and wherein a private key of each client terminal is not shared by any other client terminal; and transmitting the third summed encrypted data to the first client terminal for decryption and playing back by the first client terminal.