SYSTEM AND METHOD FOR PERFORMING A SECURE CRYPTOGRAPHIC OPERATION ON A MOBILE DEVICE BASED ON A CONTEXTUAL VARIABLE

摘要

In a mobile communication device, multiple sets of sensor measurement data are obtained, each from a corresponding hardware sensor resident on the device. Insufficiently random data is filtered from each of the data sets to produce random data sets Which are combined to produce entropy data which is stored in an entropy data cache. An entropy pool is monitored to determine a level of entropy data available and, based on the level determined, entropy data is provided from the entropy data cache to the entropy pool. Entropy data from the entropy pool is then applied to perform a cryptographic operation such as the generation of an encryption key for encrypting communications sent or received by the mobile communication device.

主权项

1. A method of performing a secure cryptographic operation, the method performed by a mobile communication device and comprising the steps of:
obtaining multiple sets of sensor measurement data, each being obtained from a corresponding one of multiple hardware sensors resident on the mobile communication device; determining an entropy strength of each of the multiple sets of sensor measurement data; selecting a threshold value from among multiple threshold values based on a context variable indicative of a context of a communication to be performed with the mobile communication device; selecting a set of sensor measurement data to be included as entropy data only if the determined entropy strength meets the selected threshold value; and applying the entropy data to encrypt data to be communicated over the mobile communication device.