A system and method for searching and retrieving certificates, which may
be used in the processing of encoded messages. In one broad aspect, a
method is provided in which a certificate search request is received, a
search of one or more certificate servers for certificates satisfying the
request is performed, located certificates are retrieved and processed at
a first computing device to determine data that uniquely identifies each
located certificate, and search result data comprising the determined
data is communicated to a second device (e.g. a mobile device) for use in
determining whether each located certificate is already stored on the
second device.