Data leakage prevention for resource limited device

A method of screening a file on a mobile computing device, said mobile computing device subject to a DLP (data leakage prevention) policy of an enterprise, said method comprising:

• determining that a triggering event has occurred on said mobile computing device, said triggering event including an identification of a digital file on said mobile device;
• determining that said triggering event is an event covered by said DLP policy, said DLP policy being stored in a database on said mobile device;
• determining a unique characteristic of said digital file;
• searching a local signature database of said mobile device to determine whether said unique characteristic of said digital file is present within said local signature database, wherein said local signature database is a subset of calculated digital signatures sent by a computer of said enterprise having a global signature database;
• and
• when it is determined that said unique characteristic is present within said local signature database, blocking said triggering event from occurring on said mobile device.

A method of filtering digital signatures from a mobile computing device, said method comprising:

• generating a database of digital signatures, each digital signature uniquely representing a computer file within an enterprise, wherein each of said computer files is deemed a sensitive file of said enterprise;
• establishing a network connection between said enterprise and a mobile computing device, wherein said mobile computing device is subject to a DLP (data leakage prevention) policy of said enterprise;
• receiving a plurality of digital signatures from said mobile device, said received digital signatures representing computer files present on said mobile device;
• comparing said received digital signatures with said database of digital signatures;
• and
• returning to said mobile computing device an identification of those received digital signatures that match with any of said database of digital signatures, wherein said mobile computing device is apprised of sensitive files of said enterprise.