Aspects of the invention relate to a computer-implemented method of improving the efficiency of an electronic collateralisation search engine that uses assets distributed on one or more remotely-located asset depositories. The method comprises selecting from a database of asset records of the remotely-located assets of a collateral giver, a subset of asset records having asset characteristics that satisfy a collateral giver's one or more predefined threshold criteria. Restricting a received search of collateral giver's asset records, which match a collateral receiver's query, to the subset of collateral giver's asset records.