Not really. A Faraday cage works when storing it. However, the moment you use it all information is transferred. There really isn't any privacy using a cell phone.

If you are familiar with the FitBit wrist watch for monitoring your heart, this is actually a good example of what the Smart phone and the App is for the digital ID system is all about. The FitBit transfers your medical data to the App on your computer. Do you own this? Not really. The App sends this data to FitBit Corp. They in turn process it, store it, and will sell it for profit.