SIMSec: A Key Exchange Protocol Between SIM Card and Service Provider

Abstract

Mobile technology is so popular and overdosed adoption is inevitable in today's world. As the mobile technologies have advanced, Service Providers (SP) have offered services via Smartphones and some of them required secure data communication between the Subscriber Identity Module (SIM) cards on Smartphones and the servers of SP. The latest SIM cards comply with recent specifications including secure domain generation, mobile signatures, pre-installed encryption keys, and other useful security services. Nevertheless, un-keyed SIM cards do not satisfy such requirements, thus end-to-end encryption between the SIM card and SP cannot be provided. In this paper, we provide a key exchange protocol, which creates a symmetric key through the collaborative work of the SIM card and the SP server. After a successful protocol performance, the SIM card and SP can perform end-to-end data encryption. After defining the protocol, we also discuss the security issues and provide a formal security analysis of the protocol using the Casper/FDR tool.