BURAK BAYOGLU
TUBITAK - UEKAE, National Research Institute of Electronics and Cryptology, Gebze, TR-41470, Kocaeli, Turkey

ALBERT LEVI, ERKAY SAVAS
Sabanci University, Fac. of Eng. & Nat. Sci., Orhanli, Tuzla, TR-34956, Istanbul, Turkey

In this paper we analyze the performance of end-to-end security in wireless applications. WTLS (Wireless Transport Layer Security) handshake protocol is used as the key security protocol. Several scenarios and different cryptosystems are considered. We took an experimental approach and implemented the protocols and necessary crypto primitives in both wireless handheld device and server. Tests are performed over a GSM provider network. Processing, queuing and transmission delays are considered in the analysis. Results are interpreted from both client and the server points of view. Not only the key sizes proposed by the WTLS standard, but also stronger key sizes are tested. Results show that (i) Elliptic Curve Cryptosystems (ECC) perform better than RSA cryptosystem, and (ii) it is possible to use ECC key sizes larger than the ones proposed in the WTLS standard without significant performance degradation. In our tests, GSM CSD and GPRS bearers are taken into account. Another interesting result is that the these two bearers perform close to each other in WTLS handshake protocol because of similar and significant traversal delays in both bearers.