10. The system of claim 8 , wherein the computer-readable storage medium further comprises one or more programming instructions that, when executed, cause the mobile electronic device to: generate a randomness value, and send the randomness value to the computational tag to use to generate the encrypted key.
10. The system of claim 8 , wherein the computer-readable storage medium further comprises one or more programming instructions that, when executed, cause the mobile electronic device to: generate a randomness value, and send the randomness value to the computational tag to use to generate the encrypted key. 11. The system of claim 10 , wherein the one or more programming instructions that, when executed, cause the mobile electronic device to generate the randomness value comprise one or more programming instructions that, when executed, cause the mobile electronic device to: record a pattern of fluctuations of the mobile electronic device over a period of time; and generate the randomness value using the pattern of fluctuations.