Karsten Nohl and Sylvain Munaut demonstrated their eavesdropping toolkit at the Chaos Computer Club Congress (CCC) in Berlin.
The work builds on earlier research that has found holes in many parts of the most widely used mobile technology.
The pair spent a year putting together the parts of the eavesdropping toolkit.
"Now there's a path from your telephone number to me finding you and listening to your calls," Mr Nohl told BBC News. "The whole way."
He said many of the pieces in the eavesdropping toolkit already existed thanks to work by other security researchers but there was one part the pair had to create themselves.
"The one piece that completed the chain was the ability to record data off the air," he said.
In a demonstration at the CCC, the pair took attendees through all the steps that led from locating a particular phone to seizing its unique ID, then leap-frogging from that to getting hold of data swapped between a handset and a base station as calls are made and texts sent.
More info here: http://www.bbc.co.uk/news/technology-12094227