Patent ID: 9166794
Filing Date: 2015-10-20
Classification: H04L,H04W

Abstract:
1. At a mobile wireless communication device, a method of processing an electronic message, said method comprising: detecting receipt of an instruction to sign a composite message, where said composite message is formed by a server associated with said mobile wireless communication device, said composite message including a new message portion and an original message, and only an initial portion of said original message is available at said mobile wireless communication device; generating an access key; inserting a record in a table, stored at said mobile wireless communication device, said record including said access key and a secondary value for use in obtaining a private cryptographic key; transmitting a processing request to said server associated with said mobile wireless communication device, said processing request including said new message portion, a reference to said original message, and said access key; receiving a signing request from said server, said signing request including a received access key and a hash of said composite message; locating in said table, the record with the access key that matches said received access key; extracting, from said record, said secondary value; obtaining said private cryptographic key by using said secondary value; employing said private cryptographic key to sign said hash to form a digital signature; and transmitting said digital signature to said server.