On Measuring SSL-based Secure Data Transfer with Handheld Devices

摘要

The Secure Sockets Layer (SSL) security protocol is largely used nowadays by the World Wide Web to secure Internet communications and an increasing number of handheld devices are provided by the manufactures with preinstalled applications (e.g. web browsers) and digital certificates in order to support SSL in wireless environments too. We present first a comprehensive analysis of SSL protocol and the cryptographic algorithms used as building blocks in the protocol. We demonstrate next that SSL support embedded also in other applications for some mobile devices does not impact significantly on overall application's performance when communicating with other parties. We wanted to use for our experimental setup, APIs and tools that are either available for the majority of the handheld devices or that can be downloaded and tested freely and without major modifications. This is the especially the case of application developers, who preferably would not use modified versions of cryptographic libraries and special drivers characteristic to academic/commercial testing environments. We also developed a tool named SSLPerf (SSL Performance) for testing SSL security protocol's performance when transferring either small amounts of data (e.g. credit card number) or of medium dimension (e.g. a document in PDF format), with handheld devices. We've compared the results obtained with SSLPerf on Windows CE-enabled Handheld and Pocket PCs and 'powerful' Windows 2000/XP-enabled platforms with other related works.