Microsoft Word - IMECS2011_Draft_Guo_and_Yu_fixed_20101229_2

In current mobile telecommunications systems, the security offered by these networks are limited. In order to be used in use cases that require a high degree of security, such as M2M (financial, voting system), more security guarantees are necessary. Therefore, additional security must be added on top of existing networks. A common way to add security is by the use of composite encryption schemes. Two (2) of these schemes are then compared in terms of performance: an Encrypt-and-MAC composite scheme represented by AES in CTR mode and in CMAC mode and an Encrypt-then-MAC scheme using the EAX mode. These schemes are used in the context of an over the top protocol in SMS networks used in M2M applications. Results show that performance in terms of transaction time is close between the two (2) composite schemes but the Encrypt-then-MAC scheme provides more guarantees. It is also show that online performance is better for the Encrypt-then-MAC composite scheme.